Fix GCC 4.7 warnings.

* src/string-search.h (StringSearch): Avoid -Werror=strict-overflow
  warning.

Review URL: http://codereview.chromium.org/8947022
Patch from Tobias Burnus <burnus@net-b.de>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10295 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/string-search.h

@@ -369,6 +369,10 @@ void StringSearch<PatternChar, SubjectChar>::PopulateBoyerMooreTable() {
   shift_table[pattern_length] = 1;
   suffix_table[pattern_length] = pattern_length + 1;
 
+  if (pattern_length <= start) {
+    return;
+  }
+
   // Find suffixes.
   PatternChar last_char = pattern[pattern_length - 1];
   int suffix = pattern_length + 1;