Slightly improved register assignment for %_IsObject on IA32 and ARM.

src/ia32/lithium-ia32.h

Index: src/ia32/lithium-ia32.h
===================================================================
--- src/ia32/lithium-ia32.h	(revision 8444)
+++ src/ia32/lithium-ia32.h	(working copy)
@@ -692,23 +692,21 @@
 };
 
 
-class LIsObject: public LTemplateInstruction<1, 1, 1> {
+class LIsObject: public LTemplateInstruction<1, 1, 0> {
  public:
-  LIsObject(LOperand* value, LOperand* temp) {
+  explicit LIsObject(LOperand* value) {
     inputs_[0] = value;
-    temps_[0] = temp;
   }
 
   DECLARE_CONCRETE_INSTRUCTION(IsObject, "is-object")
 };
 
 
-class LIsObjectAndBranch: public LControlInstruction<1, 2> {
+class LIsObjectAndBranch: public LControlInstruction<1, 1> {
  public:
-  LIsObjectAndBranch(LOperand* value, LOperand* temp, LOperand* temp2) {
+  LIsObjectAndBranch(LOperand* value, LOperand* temp) {
     inputs_[0] = value;
     temps_[0] = temp;
-    temps_[1] = temp2;
   }
 
   DECLARE_CONCRETE_INSTRUCTION(IsObjectAndBranch, "is-object-and-branch")