Prepare push to trunk. Now working on version 3.21.6.

R=jkummerow@chromium.org
BUG=

Review URL: https://chromiumcodereview.appspot.com/23494008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16382 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

ChangeLog

+2013-08-28: Version 3.21.5
+
+        Fixed compilation with recent MinGW64 versions. (issue 2300)
+
+        Added RemovePrototype to FunctionTemplate. (Chromium issue 272440)
+
+        Performance and stability improvements on all platforms.
+
+
 2013-08-26: Version 3.21.4
 
         Lowered kInitialMaxFastElementArray constant to 95K (issue 2790).

src/version.cc

@@ -34,7 +34,7 @@
 // system so their names cannot be changed without changing the scripts.
 #define MAJOR_VERSION     3
 #define MINOR_VERSION     21
-#define BUILD_NUMBER      5
+#define BUILD_NUMBER      6
 #define PATCH_LEVEL       0
 // Use 1 for candidates and 0 otherwise.
 // (Boolean macro values are not supported by all preprocessors.)