[ASTReader] Add test for previous change r306583 / 145692e.

Summary:
Add a test for the change to ASTReader that reproduces the
logic for consolidating multiple ObjC interface definitions to the
case of multiple ObjC protocol definitions.

This test is a modified copy of the test that accompanied the original
change to interfaces, in 2ba1979.

Reviewers: bruno

Reviewed By: bruno

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D34788

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@306732 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit f832c35ecbbbe989774fd6b1e4fd84a8199b5dcd)
diff --git a/test/Modules/Inputs/lookup-assert-protocol/Base.h b/test/Modules/Inputs/lookup-assert-protocol/Base.h
new file mode 100644
index 0000000..5c9506f
--- /dev/null
+++ b/test/Modules/Inputs/lookup-assert-protocol/Base.h
@@ -0,0 +1,3 @@
+@protocol BaseProtocol
+- (void) test;
+@end
diff --git a/test/Modules/Inputs/lookup-assert-protocol/Derive.h b/test/Modules/Inputs/lookup-assert-protocol/Derive.h
new file mode 100644
index 0000000..fdcde61
--- /dev/null
+++ b/test/Modules/Inputs/lookup-assert-protocol/Derive.h
@@ -0,0 +1,4 @@
+#include "Base.h"
+@protocol DerivedProtocol<BaseProtocol>
+- (void) test2;
+@end
diff --git a/test/Modules/Inputs/lookup-assert-protocol/H3.h b/test/Modules/Inputs/lookup-assert-protocol/H3.h
new file mode 100644
index 0000000..3d8f878
--- /dev/null
+++ b/test/Modules/Inputs/lookup-assert-protocol/H3.h
@@ -0,0 +1 @@
+#include "Base.h"
diff --git a/test/Modules/Inputs/lookup-assert-protocol/module.map b/test/Modules/Inputs/lookup-assert-protocol/module.map
new file mode 100644
index 0000000..e8a89eb
--- /dev/null
+++ b/test/Modules/Inputs/lookup-assert-protocol/module.map
@@ -0,0 +1,4 @@
+module X {
+  header "H3.h"
+  export *
+}
diff --git a/test/Modules/lookup-assert-protocol.m b/test/Modules/lookup-assert-protocol.m
new file mode 100644
index 0000000..3c093f1
--- /dev/null
+++ b/test/Modules/lookup-assert-protocol.m
@@ -0,0 +1,17 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fmodules-cache-path=%t -fmodules -fimplicit-module-maps -I %S/Inputs/lookup-assert-protocol %s -verify
+// expected-no-diagnostics
+
+#include "Derive.h"
+#import <H3.h>
+
+__attribute__((objc_root_class))
+@interface Thing<DerivedProtocol>
+@end
+
+@implementation Thing
+- (void)test {
+}
+- (void)test2 {
+}
+@end