remove most uses of Isolate::Current in arch specific files

src/ia32/assembler-ia32-inl.h

Index: src/ia32/assembler-ia32-inl.h
diff --git a/src/ia32/assembler-ia32-inl.h b/src/ia32/assembler-ia32-inl.h
index b6ef242a2c4e5350a0d207ce9cfcdd4fa6581217..5a35b207f72db72a94bb20a2a8a8b5ef5b1f9127 100644
--- a/src/ia32/assembler-ia32-inl.h
+++ b/src/ia32/assembler-ia32-inl.h
@@ -251,7 +251,7 @@ bool RelocInfo::IsPatchedDebugBreakSlotSequence() {
 }
 
 
-void RelocInfo::Visit(ObjectVisitor* visitor) {
+void RelocInfo::Visit(Isolate* isolate, ObjectVisitor* visitor) {
   RelocInfo::Mode mode = rmode();
   if (mode == RelocInfo::EMBEDDED_OBJECT) {
     visitor->VisitEmbeddedPointer(this);
@@ -266,12 +266,11 @@ void RelocInfo::Visit(ObjectVisitor* visitor) {
   } else if (RelocInfo::IsCodeAgeSequence(mode)) {
     visitor->VisitCodeAgeSequence(this);
   #ifdef ENABLE_DEBUGGER_SUPPORT
-  // TODO(isolates): Get a cached isolate below.
   } else if (((RelocInfo::IsJSReturn(mode) &&
               IsPatchedReturnSequence()) ||
              (RelocInfo::IsDebugBreakSlot(mode) &&
               IsPatchedDebugBreakSlotSequence())) &&
-             Isolate::Current()->debug()->has_break_points()) {
+             isolate->debug()->has_break_points()) {
     visitor->VisitDebugTarget(this);
 #endif
   } else if (IsRuntimeEntry(mode)) {
@@ -329,14 +328,11 @@ Immediate::Immediate(Label* internal_offset) {
 
 
 Immediate::Immediate(Handle<Object> handle) {
-#ifdef DEBUG
-  Isolate* isolate = Isolate::Current();
-#endif
   AllowDeferredHandleDereference using_raw_address;
   // Verify all Objects referred by code are NOT in new space.
   Object* obj = *handle;
-  ASSERT(!isolate->heap()->InNewSpace(obj));
   if (obj->IsHeapObject()) {
+    ASSERT(!HeapObject::cast(obj)->GetHeap()->InNewSpace(obj));
     x_ = reinterpret_cast<intptr_t>(handle.location());
     rmode_ = RelocInfo::EMBEDDED_OBJECT;
   } else {