Disable GC stress for mjsunit/fast-prototype.

R=yangguo@chromium.org
TEST=mjsunit/fast-prototype --gc-interval=500 --stress-compaction

Review URL: https://codereview.chromium.org/11534004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13190 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

test/mjsunit/fast-prototype.js

@@ -27,6 +27,10 @@
 
 // Flags: --allow-natives-syntax
 
+// TODO(mstarzinger): This test does not succeed when GCs happen in
+// between prototype transitions, we disable GC stress for now.
+// Flags: --noincremental-marking
+
 // Check that objects that are used for prototypes are in the fast mode.
 
 function Super() {