Limit end-anchored regexps to testing end of string where possible.

src/regexp-macro-assembler-irregexp.cc

Index: src/regexp-macro-assembler-irregexp.cc
diff --git a/src/regexp-macro-assembler-irregexp.cc b/src/regexp-macro-assembler-irregexp.cc
index 90abe912fa701afbd04bf5c5effa26423fbf399f..6fbb14adda8b1fb07bbd90c3fd7d9badcf2e7791 100644
--- a/src/regexp-macro-assembler-irregexp.cc
+++ b/src/regexp-macro-assembler-irregexp.cc
@@ -145,6 +145,12 @@ void RegExpMacroAssemblerIrregexp::ReadStackPointerFromRegister(
 }
 
 
+void RegExpMacroAssemblerIrregexp::SetCurrentPositionFromEnd(int by) {
+  ASSERT(is_uint24(by));
+  Emit(BC_SET_CURRENT_POSITION_FROM_END, by);
+}
+
+
 void RegExpMacroAssemblerIrregexp::SetRegister(int register_index, int to) {
   ASSERT(register_index >= 0);
   ASSERT(register_index <= kMaxRegister);