Prepare push to trunk. Now working on version 3.21.8.

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/23460012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16445 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

ChangeLog

+2013-08-30: Version 3.21.7
+
+        Fixed casts of eternal handles.
+
+        Turned on global handle zapping.
+
+        Always visit branches during HGraph building (Chromium issue 280333).
+
+        Profiler changes: removed deprecated API, support higher sampling
+        rate on Windows.
+
+        Performance and stability improvements on all platforms.
+
+
 2013-08-29: Version 3.21.6
 
         Fixed inlined 'throw' statements interfering with live range

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      7
+#define BUILD_NUMBER      8
 #define PATCH_LEVEL       0
 // Use 1 for candidates and 0 otherwise.
 // (Boolean macro values are not supported by all preprocessors.)