Make x87 stack tracking more robust and avoid spilling

src/ia32/lithium-ia32.cc

Index: src/ia32/lithium-ia32.cc
diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index 2c4799e632e026f02d5afbcbec13c8c13a44e664..a771aa882265760a0a753c5a41d26579a450c92b 100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -1029,7 +1029,7 @@ LEnvironment* LChunkBuilder::CreateEnvironment(
 
 
 LInstruction* LChunkBuilder::DoGoto(HGoto* instr) {
-  return new(zone()) LGoto(instr->FirstSuccessor()->block_id());
+  return new(zone()) LGoto(instr->FirstSuccessor());
 }
 
 
@@ -1041,7 +1041,7 @@ LInstruction* LChunkBuilder::DoBranch(HBranch* instr) {
     HBasicBlock* successor = HConstant::cast(value)->BooleanValue()
         ? instr->FirstSuccessor()
         : instr->SecondSuccessor();
-    return new(zone()) LGoto(successor->block_id());
+    return new(zone()) LGoto(successor);
   }
 
   ToBooleanStub::Types expected = instr->expected_input_types();