Revert "Inline instance object hash code into object header on 64 bit."

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 3b97a1bf80b551b928e90e98d4abb018a306f006..f0ca5913f9164fb4d092aecb7eee663df629afac 100644
--- a/runtime/vm/intrinsifier_x64.cc
+++ b/runtime/vm/intrinsifier_x64.cc
@@ -1754,23 +1754,6 @@ void Intrinsifier::String_getHashCode(Assembler* assembler) {
 }
 
 
-void Intrinsifier::Object_getHash(Assembler* assembler) {
-  __ movq(RAX, Address(RSP, +1 * kWordSize));  // Object.
-  __ movl(RAX, FieldAddress(RAX, String::hash_offset()));
-  __ SmiTag(RAX);
-  __ ret();
-}
-
-
-void Intrinsifier::Object_setHash(Assembler* assembler) {
-  __ movq(RAX, Address(RSP, +2 * kWordSize));  // Object.
-  __ movq(RDX, Address(RSP, +1 * kWordSize));  // Value.
-  __ SmiUntag(RDX);
-  __ movl(FieldAddress(RAX, String::hash_offset()), RDX);
-  __ ret();
-}
-
-
 void GenerateSubstringMatchesSpecialization(Assembler* assembler,
                                             intptr_t receiver_cid,
                                             intptr_t other_cid,