Include multiplication in the megamorphic cache hash to avoid cid ranges overlapping modulo table s…

runtime/vm/stub_code_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"
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 2088 matching lines @@
 
 
 void StubCode::EmitMegamorphicLookup(Assembler* assembler) {
   __ LoadTaggedClassIdMayBeSmi(R0, R0);
   // R0: class ID of the receiver (smi).
   __ ldr(R4, FieldAddress(R5, MegamorphicCache::arguments_descriptor_offset()));
   __ ldr(R2, FieldAddress(R5, MegamorphicCache::buckets_offset()));
   __ ldr(R1, FieldAddress(R5, MegamorphicCache::mask_offset()));
   // R2: cache buckets array.
   // R1: mask.
-  __ mov(R3, R0);
+  __ LoadImmediate(TMP, MegamorphicCache::kSpreadFactor);
+  __ mul(R3, R0, TMP);
   // R3: probe.
 
   Label loop, update, load_target_function;
   __ b(&loop);
 
   __ Bind(&update);
   __ add(R3, R3, Operand(Smi::RawValue(1)));
   __ Bind(&loop);
   __ and_(R3, R3, Operand(R1));
   const intptr_t base = Array::data_offset();
@@ skipping 109 matching lines @@
 }
 
 
 void StubCode::GenerateFrameAwaitingMaterializationStub(Assembler* assembler) {
   __ brk(0);
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64