Specialize breakpoint stubs by set of live registers of the stubs they are intercepting.

runtime/vm/runtime_entry_ia32.cc

 // Copyright (c) 2011, 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_IA32)
 
 #include "vm/runtime_entry.h"
 
 #include "vm/assembler.h"
@@ skipping 13 matching lines @@
 // For leaf calls the caller is responsible to setup the arguments
 // and look for return values based on the C calling convention.
 void RuntimeEntry::Call(Assembler* assembler, intptr_t argument_count) const {
   if (is_leaf()) {
     ASSERT(argument_count == this->argument_count());
     ExternalLabel label(GetEntryPoint());
     __ call(&label);
   } else {
     // Argument count is not checked here, but in the runtime entry for a more
     // informative error message.
+    ASSERT((GetEntryPoint() & kSmiTagMask) == 0);
     __ movl(ECX, Immediate(GetEntryPoint()));
-    __ movl(EDX, Immediate(Smi::RawValue(argument_count)));
+    __ movl(EDX, Immediate(argument_count));
     __ call(&StubCode::CallToRuntimeLabel());
   }
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32