Remove deprecated Megamorphic stub.

runtime/vm/stub_code_x64.cc

 // Copyright (c) 2013, 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_X64)
 
 #include "vm/assembler.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 1429 matching lines @@
 }
 
 
 // Do not count as no type feedback is collected.
 void StubCode::GenerateClosureCallInlineCacheStub(Assembler* assembler) {
   GenerateNArgsCheckInlineCacheStub(
       assembler, 1, kInlineCacheMissHandlerOneArgRuntimeEntry);
 }
 
 
-// Megamorphic call is currently implemented as IC call but through a stub
-// that does not check/count function invocations.
-void StubCode::GenerateMegamorphicCallStub(Assembler* assembler) {
-  GenerateNArgsCheckInlineCacheStub(
-      assembler, 1, kInlineCacheMissHandlerOneArgRuntimeEntry);
-}
-
-
 // Intermediary stub between a static call and its target. ICData contains
 // the target function and the call count.
 // RBX: ICData
 void StubCode::GenerateZeroArgsUnoptimizedStaticCallStub(Assembler* assembler) {
   GenerateUsageCounterIncrement(assembler, RCX);
 #if defined(DEBUG)
   { Label ok;
     // Check that the IC data array has NumArgsTested() == 0.
     // 'NumArgsTested' is stored in the least significant bits of 'state_bits'.
     __ movl(RCX, FieldAddress(RBX, ICData::state_bits_offset()));
@@ skipping 377 matching lines @@
 
   __ movq(left, Address(RSP, 2 * kWordSize));
   __ movq(right, Address(RSP, 1 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64