CSA fast path for Map.prototype.(Get|Has) for string keys.

src/code-stub-assembler.cc

Index: src/code-stub-assembler.cc
diff --git a/src/code-stub-assembler.cc b/src/code-stub-assembler.cc
index 538450b43b0912eba9dd78d337c1cb12ae844181..924c4946c020ba57fece4b32c63433c68c97b04d 100644
--- a/src/code-stub-assembler.cc
+++ b/src/code-stub-assembler.cc
@@ -1220,7 +1220,7 @@ Node* CodeStubAssembler::LoadNameHashField(Node* name) {
 Node* CodeStubAssembler::LoadNameHash(Node* name, Label* if_hash_not_computed) {
   Node* hash_field = LoadNameHashField(name);
   if (if_hash_not_computed != nullptr) {
-    GotoIf(IsClearWord32(hash_field, Name::kHashNotComputedMask),
+    GotoIf(IsSetWord32(hash_field, Name::kHashNotComputedMask),
            if_hash_not_computed);
   }
   return Word32Shr(hash_field, Int32Constant(Name::kHashShift));