Disable all tests that rely on swift-build.

swift-build is not included in the 2.2 package.
diff --git a/swift-build.py b/swift-build.py
index bfc2c46..c105074 100644
--- a/swift-build.py
+++ b/swift-build.py
@@ -1,5 +1,8 @@
 # Trivial test for Swift build.
 #
+# No swift-build in 2.2
+# REQUIRES: disabled
+#
 # Make a sandbox dir.
 # RUN: rm -rf %t.dir
 # RUN: mkdir -p %t.dir/tool
diff --git a/swift-package-with-spaces.py b/swift-package-with-spaces.py
index d2f0268..7d46046 100644
--- a/swift-package-with-spaces.py
+++ b/swift-package-with-spaces.py
@@ -1,5 +1,8 @@
 # Check a package with spaces.
 #
+# No swift-build in 2.2
+# REQUIRES: disabled
+#
 # Make a sandbox dir.
 # RUN: rm -rf %t.dir
 # RUN: mkdir -p %t.dir/more\ spaces/special\ tool
diff --git a/test-foundation-package/test-foundation-package.py b/test-foundation-package/test-foundation-package.py
index 3e2450e..d534f25 100644
--- a/test-foundation-package/test-foundation-package.py
+++ b/test-foundation-package/test-foundation-package.py
@@ -1,5 +1,9 @@
 # Trivial test for importing Foundation
 #
+#
+# No swift-build in 2.2
+# REQUIRES: disabled
+#
 # 
 # Make a sandbox dir.
 # RUN: rm -rf %t.dir
diff --git a/test-xctest-package/test-xctest-package.py b/test-xctest-package/test-xctest-package.py
index 3c0bd9a..302a913 100644
--- a/test-xctest-package/test-xctest-package.py
+++ b/test-xctest-package/test-xctest-package.py
@@ -1,6 +1,9 @@
 # Trivial test for importing XCTest.
 #
-
+#
+# No swift-build in 2.2
+# REQUIRES: disabled
+#
 # This test doesn't work on Darwin yet, because the XCTest overlay isn't shipped
 # with the package, and can't be found:#
 #   <rdar://problem/23600043> Cannot import XCTest with swift from a downloadable package