Port irregexp bytecode compiler and interpreter from V8 r24065.

runtime/vm/intrinsifier_arm.cc

Index: runtime/vm/intrinsifier_arm.cc
diff --git a/runtime/vm/intrinsifier_arm.cc b/runtime/vm/intrinsifier_arm.cc
index 4ba8fedd2f7aabd1601694702323ddfec74ab1a1..f72ec801d291130c53f0271135531551d631db64 100644
--- a/runtime/vm/intrinsifier_arm.cc
+++ b/runtime/vm/intrinsifier_arm.cc
@@ -18,6 +18,8 @@
 
 namespace dart {
 
+DECLARE_FLAG(bool, interpret_irregexp);
+
 // When entering intrinsics code:
 // R5: IC Data
 // R4: Arguments descriptor
@@ -1962,6 +1964,8 @@ void Intrinsifier::TwoByteString_equality(Assembler* assembler) {
 
 
 void Intrinsifier::JSRegExp_ExecuteMatch(Assembler* assembler) {
+  if (FLAG_interpret_irregexp) return;
+
   static const intptr_t kRegExpParamOffset = 2 * kWordSize;
   static const intptr_t kStringParamOffset = 1 * kWordSize;
   // start_index smi is located at offset 0.