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

runtime/vm/intrinsifier_arm64.cc

Index: runtime/vm/intrinsifier_arm64.cc
diff --git a/runtime/vm/intrinsifier_arm64.cc b/runtime/vm/intrinsifier_arm64.cc
index 3c5f4f6c341544c753153f0fa936edda62308192..80d51eb3e4c0c564710339473e61c281d61f3275 100644
--- a/runtime/vm/intrinsifier_arm64.cc
+++ b/runtime/vm/intrinsifier_arm64.cc
@@ -1832,23 +1832,6 @@ void Intrinsifier::String_getHashCode(Assembler* assembler) {
 }
 
 
-void Intrinsifier::Object_getHash(Assembler* assembler) {
-  __ ldr(R0, Address(SP, 0 * kWordSize));
-  __ ldr(R0, FieldAddress(R0, String::hash_offset()), kUnsignedWord);
-  __ SmiTag(R0);
-  __ ret();
-}
-
-
-void Intrinsifier::Object_setHash(Assembler* assembler) {
-  __ ldr(R0, Address(SP, 1 * kWordSize));  // Object.
-  __ ldr(R1, Address(SP, 0 * kWordSize));  // Value.
-  __ SmiUntag(R1);
-  __ str(R1, FieldAddress(R0, String::hash_offset()), kUnsignedWord);
-  __ ret();
-}
-
-
 void GenerateSubstringMatchesSpecialization(Assembler* assembler,
                                             intptr_t receiver_cid,
                                             intptr_t other_cid,