VM: Optimize RegExp.matchAsPrefix(...) by generating a sticky RegExp specialization.

runtime/vm/intrinsifier_x64.cc

Index: runtime/vm/intrinsifier_x64.cc
diff --git a/runtime/vm/intrinsifier_x64.cc b/runtime/vm/intrinsifier_x64.cc
index b888804ec48014899ce266223dccc7c3d406fc48..fa250d4a6e1026ea105c092a5e4471a990931ee2 100644
--- a/runtime/vm/intrinsifier_x64.cc
+++ b/runtime/vm/intrinsifier_x64.cc
@@ -2192,7 +2192,8 @@ void Intrinsifier::TwoByteString_equality(Assembler* assembler) {
 }
 
 
-void Intrinsifier::RegExp_ExecuteMatch(Assembler* assembler) {
+void Intrinsifier::IntrinsifyRegExpExecuteMatch(Assembler* assembler,
+                                                bool sticky) {
   if (FLAG_interpret_irregexp) return;
 
   static const intptr_t kRegExpParamOffset = 3 * kWordSize;
@@ -2210,8 +2211,8 @@ void Intrinsifier::RegExp_ExecuteMatch(Assembler* assembler) {
   __ movq(RDI, Address(RSP, kStringParamOffset));
   __ LoadClassId(RDI, RDI);
   __ SubImmediate(RDI, Immediate(kOneByteStringCid));
-  __ movq(RAX, FieldAddress(RBX, RDI, TIMES_8,
-                            RegExp::function_offset(kOneByteStringCid)));
+  __ movq(RAX, FieldAddress(RBX, RDI, TIMES_8, RegExp::function_offset(
+                                                   kOneByteStringCid, sticky)));
 
   // Registers are now set up for the lazy compile stub. It expects the function
   // in RAX, the argument descriptor in R10, and IC-Data in RCX.