Fix issue 20190: Mark Uint32/Int32 typed data load to produce a Mint always

runtime/vm/intermediate_language_arm64.cc

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 935 matching lines @@
     case kTypedDataUint32ArrayCid:
       return CompileType::FromCid(kSmiCid);
 
     default:
       UNIMPLEMENTED();
       return CompileType::Dynamic();
   }
 }
 
 
+bool  LoadIndexedInstr::Typed32BitIsSmi() const { return true; }
+
+
 Representation LoadIndexedInstr::representation() const {
   switch (class_id_) {
     case kArrayCid:
     case kImmutableArrayCid:
     case kTypedDataInt8ArrayCid:
     case kTypedDataUint8ArrayCid:
     case kTypedDataUint8ClampedArrayCid:
     case kExternalTypedDataUint8ArrayCid:
     case kExternalTypedDataUint8ClampedArrayCid:
     case kTypedDataInt16ArrayCid:
@@ skipping 4346 matching lines @@
   compiler->GenerateCall(token_pos(), &label, stub_kind_, locs());
 #if defined(DEBUG)
   __ LoadImmediate(R4, kInvalidObjectPointer, kNoPP);
   __ LoadImmediate(R5, kInvalidObjectPointer, kNoPP);
 #endif
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64