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

runtime/vm/flow_graph_compiler_ia32.cc

Index: runtime/vm/flow_graph_compiler_ia32.cc
diff --git a/runtime/vm/flow_graph_compiler_ia32.cc b/runtime/vm/flow_graph_compiler_ia32.cc
index 25d3fd95da2b963690161b3dd02dc09fe162f3f3..cf875b5f782cd6678c6055313d83a4ced13840f9 100644
--- a/runtime/vm/flow_graph_compiler_ia32.cc
+++ b/runtime/vm/flow_graph_compiler_ia32.cc
@@ -1182,7 +1182,6 @@ void FlowGraphCompiler::EmitUnoptimizedStaticCall(
     UNIMPLEMENTED();
   }
   ExternalLabel target_label(label_address);
-  __ movl(EDX, Immediate(0));
   __ LoadObject(ECX, ic_data);
   GenerateDartCall(deopt_id,
                    token_pos,
@@ -1243,7 +1242,6 @@ void FlowGraphCompiler::EmitInstanceCall(ExternalLabel* target_label,
                                          intptr_t token_pos,
                                          LocationSummary* locs) {
   ASSERT(Array::Handle(ic_data.arguments_descriptor()).Length() > 0);
-  __ movl(EDX, Immediate(0));
   __ LoadObject(ECX, ic_data);
   GenerateDartCall(deopt_id,
                    token_pos,
@@ -1383,8 +1381,6 @@ void FlowGraphCompiler::EmitEqualityRegRegCompare(Register left,
     if (is_optimizing()) {
       __ call(&StubCode::OptimizedIdenticalWithNumberCheckLabel());
     } else {
-      __ movl(EDX, Immediate(0));
-      __ movl(ECX, Immediate(0));
       __ call(&StubCode::UnoptimizedIdenticalWithNumberCheckLabel());
     }
     if (token_pos != Scanner::kNoSourcePos) {