Remove the patching of the debug break stub

This is no longer required to break at the function entry. Actually has not been required since the inlined stack check was introduced long time ago.
Review URL: http://codereview.chromium.org/4106005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5726 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/debug.cc

@@ -1464,8 +1464,7 @@ bool Debug::IsSourceBreakStub(Code* code) {
 // location.
 bool Debug::IsBreakStub(Code* code) {
   CodeStub::Major major_key = CodeStub::GetMajorKey(code);
-  return major_key == CodeStub::CallFunction ||
-         major_key == CodeStub::StackCheck;
+  return major_key == CodeStub::CallFunction;
 }
 
 
@@ -1503,8 +1502,7 @@ Handle<Code> Debug::FindDebugBreak(Handle<Code> code, RelocInfo::Mode mode) {
     return result;
   }
   if (code->kind() == Code::STUB) {
-    ASSERT(code->major_key() == CodeStub::CallFunction ||
-           code->major_key() == CodeStub::StackCheck);
+    ASSERT(code->major_key() == CodeStub::CallFunction);
     Handle<Code> result =
         Handle<Code>(Builtins::builtin(Builtins::StubNoRegisters_DebugBreak));
     return result;