Optimized megamorphic stubs

runtime/vm/flow_graph_compiler_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/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 1307 matching lines @@
     __ CompareRegisters(R0, ZR);
     __ b(&done, NE);
     __ mov(R0, R5);  // Restore receiver in R0,
 
     __ Bind(&megamorphic_call);
     __ Comment("Slow case: megamorphic call");
   }
 
   __ LoadObject(R5, cache);
   if (FLAG_use_megamorphic_stub) {
-    __ BranchLink(*StubCode::MegamorphicLookup_entry());
+    __ ldr(LR, Address(THR, Thread::megamorphic_lookup_entry_point_offset()));
+    __ blr(LR);
   } else  {
     StubCode::EmitMegamorphicLookup(assembler());
   }
   __ blr(R1);
 
   __ Bind(&done);
   RecordSafepoint(locs, slow_path_argument_count);
   const intptr_t deopt_id_after = Thread::ToDeoptAfter(deopt_id);
   if (FLAG_precompiled_mode) {
     // Megamorphic calls may occur in slow path stubs.
@@ skipping 597 matching lines @@
 void ParallelMoveResolver::RestoreFpuScratch(FpuRegister reg) {
   __ PopDouble(reg);
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64