Update protobuf version to 3.16.0-rc2 (#8556)

* Update CHANGES.txt

* Update protobuf version
diff --git a/CHANGES.txt b/CHANGES.txt
index 7c27a93..1805c9a 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -72,6 +72,8 @@
 
   Ruby
   * Fixed quadratic memory usage when appending to arrays. (#8364)
+  * Fixed memory leak of Ruby arena objects. (#8461)
+  * Add support for proto3 json_name in compiler and field definitions. (#8356)
 
   Other
   * Some doc on AOT compilation and protobuf (#8294)
diff --git a/Protobuf-C++.podspec b/Protobuf-C++.podspec
index fc3087f..df55c95 100644
--- a/Protobuf-C++.podspec
+++ b/Protobuf-C++.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name     = 'Protobuf-C++'
-  s.version  = '3.16.0-rc1'
+  s.version  = '3.16.0-rc2'
   s.summary  = 'Protocol Buffers v3 runtime library for C++.'
   s.homepage = 'https://github.com/google/protobuf'
   s.license  = '3-Clause BSD License'
diff --git a/Protobuf.podspec b/Protobuf.podspec
index 253854c..e4fd8bc 100644
--- a/Protobuf.podspec
+++ b/Protobuf.podspec
@@ -5,7 +5,7 @@
 # dependent projects use the :git notation to refer to the library.
 Pod::Spec.new do |s|
   s.name     = 'Protobuf'
-  s.version  = '3.16.0-rc1'
+  s.version  = '3.16.0-rc2'
   s.summary  = 'Protocol Buffers v.3 runtime library for Objective-C.'
   s.homepage = 'https://github.com/protocolbuffers/protobuf'
   s.license  = '3-Clause BSD License'
diff --git a/configure.ac b/configure.ac
index 5d56ac1..4fd09e0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,7 +17,7 @@
 # In the SVN trunk, the version should always be the next anticipated release
 # version with the "-pre" suffix.  (We used to use "-SNAPSHOT" but this pushed
 # the size of one file name in the dist tarfile over the 99-char limit.)
-AC_INIT([Protocol Buffers],[3.16.0-rc-1],[protobuf@googlegroups.com],[protobuf])
+AC_INIT([Protocol Buffers],[3.16.0-rc-2],[protobuf@googlegroups.com],[protobuf])
 
 AM_MAINTAINER_MODE([enable])
 
diff --git a/csharp/Google.Protobuf.Tools.nuspec b/csharp/Google.Protobuf.Tools.nuspec
index 1c6ca92..fc14480 100644
--- a/csharp/Google.Protobuf.Tools.nuspec
+++ b/csharp/Google.Protobuf.Tools.nuspec
@@ -5,7 +5,7 @@
     <title>Google Protocol Buffers tools</title>
     <summary>Tools for Protocol Buffers - Google's data interchange format.</summary>
     <description>See project site for more info.</description>
-    <version>3.16.0-rc1</version>
+    <version>3.16.0-rc2</version>
     <authors>Google Inc.</authors>
     <owners>protobuf-packages</owners>
     <licenseUrl>https://github.com/protocolbuffers/protobuf/blob/master/LICENSE</licenseUrl>
diff --git a/csharp/src/Google.Protobuf/Google.Protobuf.csproj b/csharp/src/Google.Protobuf/Google.Protobuf.csproj
index 8e5f59b..5429aad 100644
--- a/csharp/src/Google.Protobuf/Google.Protobuf.csproj
+++ b/csharp/src/Google.Protobuf/Google.Protobuf.csproj
@@ -4,7 +4,7 @@
     <Description>C# runtime library for Protocol Buffers - Google's data interchange format.</Description>
     <Copyright>Copyright 2015, Google Inc.</Copyright>
     <AssemblyTitle>Google Protocol Buffers</AssemblyTitle>
-    <VersionPrefix>3.16.0-rc1</VersionPrefix>
+    <VersionPrefix>3.16.0-rc2</VersionPrefix>
     <!-- C# 7.2 is required for Span/BufferWriter/ReadOnlySequence -->
     <LangVersion>7.2</LangVersion>
     <Authors>Google Inc.</Authors>
diff --git a/java/bom/pom.xml b/java/bom/pom.xml
index 461d6cc..4c77b5b 100644
--- a/java/bom/pom.xml
+++ b/java/bom/pom.xml
@@ -4,7 +4,7 @@
 
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-bom</artifactId>
-  <version>3.16.0-rc-1</version>
+  <version>3.16.0-rc-2</version>
   <packaging>pom</packaging>
 
   <name>Protocol Buffers [BOM]</name>
diff --git a/java/core/pom.xml b/java/core/pom.xml
index ee97fec..c473173 100644
--- a/java/core/pom.xml
+++ b/java/core/pom.xml
@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.16.0-rc-1</version>
+    <version>3.16.0-rc-2</version>
   </parent>
 
   <artifactId>protobuf-java</artifactId>
diff --git a/java/lite/pom.xml b/java/lite/pom.xml
index 7e73849..e34c94e 100644
--- a/java/lite/pom.xml
+++ b/java/lite/pom.xml
@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.16.0-rc-1</version>
+    <version>3.16.0-rc-2</version>
   </parent>
 
   <artifactId>protobuf-javalite</artifactId>
diff --git a/java/pom.xml b/java/pom.xml
index 4f8598d..a4902ab 100644
--- a/java/pom.xml
+++ b/java/pom.xml
@@ -4,7 +4,7 @@
 
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-parent</artifactId>
-  <version>3.16.0-rc-1</version>
+  <version>3.16.0-rc-2</version>
   <packaging>pom</packaging>
 
   <name>Protocol Buffers [Parent]</name>
diff --git a/java/util/pom.xml b/java/util/pom.xml
index a1cfc9b..40fab6c 100644
--- a/java/util/pom.xml
+++ b/java/util/pom.xml
@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.16.0-rc-1</version>
+    <version>3.16.0-rc-2</version>
   </parent>
 
   <artifactId>protobuf-java-util</artifactId>
diff --git a/js/package.json b/js/package.json
index 6c0e3ad..0bea4a8 100644
--- a/js/package.json
+++ b/js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "google-protobuf",
-  "version": "3.16.0-rc.1",
+  "version": "3.16.0-rc.2",
   "description": "Protocol Buffers for JavaScript",
   "main": "google-protobuf.js",
   "files": [
diff --git a/php/ext/google/protobuf/package.xml b/php/ext/google/protobuf/package.xml
index 617133c..5bc1a7d 100644
--- a/php/ext/google/protobuf/package.xml
+++ b/php/ext/google/protobuf/package.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<package packagerversion="1.9.5" version="2.0" xmlns="http://pear.php.net/dtd/package-2.0" xmlns:tasks="http://pear.php.net/dtd/tasks-1.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://pear.php.net/dtd/tasks-1.0 http://pear.php.net/dtd/tasks-1.0.xsd http://pear.php.net/dtd/package-2.0 http://pear.php.net/dtd/package-2.0.xsd">
+<package xmlns="http://pear.php.net/dtd/package-2.0" xmlns:tasks="http://pear.php.net/dtd/tasks-1.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" packagerversion="1.9.5" version="2.0" xsi:schemaLocation="http://pear.php.net/dtd/tasks-1.0 http://pear.php.net/dtd/tasks-1.0.xsd http://pear.php.net/dtd/package-2.0 http://pear.php.net/dtd/package-2.0.xsd">
  <name>protobuf</name>
  <channel>pecl.php.net</channel>
  <summary>Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data.</summary>
@@ -10,10 +10,10 @@
   <email>protobuf-opensource@google.com</email>
   <active>yes</active>
  </lead>
- <date>2021-04-02</date>
- <time>16:11:33</time>
+ <date>2021-05-03</date>
+ <time>16:40:57</time>
  <version>
-  <release>3.16.0RC1</release>
+  <release>3.16.0RC2</release>
   <api>3.16.0</api>
  </version>
  <stability>
@@ -917,5 +917,20 @@
    <notes>
    </notes>
   </release>
+  <release>
+   <version>
+    <release>3.16.0RC2</release>
+    <api>3.16.0</api>
+   </version>
+   <stability>
+    <release>beta</release>
+    <api>beta</api>
+   </stability>
+   <date>2021-05-03</date>
+   <time>16:40:57</time>
+   <license uri="https://opensource.org/licenses/BSD-3-Clause">3-Clause BSD License</license>
+   <notes>
+   </notes>
+  </release>
  </changelog>
 </package>
diff --git a/php/ext/google/protobuf/protobuf.h b/php/ext/google/protobuf/protobuf.h
index b927c9f..5cec982 100644
--- a/php/ext/google/protobuf/protobuf.h
+++ b/php/ext/google/protobuf/protobuf.h
@@ -76,7 +76,7 @@
   ZEND_ARG_INFO(0, value)
 ZEND_END_ARG_INFO()
 
-#define PHP_PROTOBUF_VERSION "3.16.0RC1"
+#define PHP_PROTOBUF_VERSION "3.16.0RC2"
 
 // ptr -> PHP object cache. This is a weak map that caches lazily-created
 // wrapper objects around upb types:
diff --git a/protoc-artifacts/pom.xml b/protoc-artifacts/pom.xml
index ddf65c8..461af3e 100644
--- a/protoc-artifacts/pom.xml
+++ b/protoc-artifacts/pom.xml
@@ -8,7 +8,7 @@
   </parent>
   <groupId>com.google.protobuf</groupId>
   <artifactId>protoc</artifactId>
-  <version>3.16.0-rc-1</version>
+  <version>3.16.0-rc-2</version>
   <packaging>pom</packaging>
   <name>Protobuf Compiler</name>
   <description>
diff --git a/python/google/protobuf/__init__.py b/python/google/protobuf/__init__.py
index 80a7bd0..51b525d 100644
--- a/python/google/protobuf/__init__.py
+++ b/python/google/protobuf/__init__.py
@@ -30,4 +30,4 @@
 
 # Copyright 2007 Google Inc. All Rights Reserved.
 
-__version__ = '3.16.0rc1'
+__version__ = '3.16.0rc2'
diff --git a/ruby/google-protobuf.gemspec b/ruby/google-protobuf.gemspec
index fab7842..e33293a 100644
--- a/ruby/google-protobuf.gemspec
+++ b/ruby/google-protobuf.gemspec
@@ -1,6 +1,6 @@
 Gem::Specification.new do |s|
   s.name        = "google-protobuf"
-  s.version     = "3.16.0.rc.1"
+  s.version     = "3.16.0.rc.2"
   git_tag       = "v#{s.version.to_s.sub('.rc.', '-rc')}" # Converts X.Y.Z.rc.N to vX.Y.Z-rcN, used for the git tag
   s.licenses    = ["BSD-3-Clause"]
   s.summary     = "Protocol Buffers"
diff --git a/src/google/protobuf/port_def.inc b/src/google/protobuf/port_def.inc
index 6761a00..0b1e58e 100644
--- a/src/google/protobuf/port_def.inc
+++ b/src/google/protobuf/port_def.inc
@@ -340,7 +340,7 @@
 #define PROTOBUF_VERSION 3016000
 #define PROTOBUF_MIN_HEADER_VERSION_FOR_PROTOC 3016000
 #define PROTOBUF_MIN_PROTOC_VERSION 3016000
-#define PROTOBUF_VERSION_SUFFIX "-rc1"
+#define PROTOBUF_VERSION_SUFFIX "-rc2"
 
 // The minimum library version which works with the current version of the
 // headers.
diff --git a/src/google/protobuf/stubs/common.h b/src/google/protobuf/stubs/common.h
index 8beedd7..55db0c3 100644
--- a/src/google/protobuf/stubs/common.h
+++ b/src/google/protobuf/stubs/common.h
@@ -85,7 +85,7 @@
 #define GOOGLE_PROTOBUF_VERSION 3016000
 
 // A suffix string for alpha, beta or rc releases. Empty for stable releases.
-#define GOOGLE_PROTOBUF_VERSION_SUFFIX "-rc1"
+#define GOOGLE_PROTOBUF_VERSION_SUFFIX "-rc2"
 
 // The minimum header version which works with the current version of
 // the library.  This constant should only be used by protoc's C++ code