Fix non-ia32 build.

src/arm/macro-assembler-arm.cc

Index: src/arm/macro-assembler-arm.cc
diff --git a/src/arm/macro-assembler-arm.cc b/src/arm/macro-assembler-arm.cc
index 6451a3c344b21f2a89a85bd1ea035bcb356fed25..2ba98f48780252777efc1bc4009039c66d737bcf 100644
--- a/src/arm/macro-assembler-arm.cc
+++ b/src/arm/macro-assembler-arm.cc
@@ -39,11 +39,14 @@
 namespace v8 {
 namespace internal {
 
-MacroAssembler::MacroAssembler(void* buffer, int size)
-    : Assembler(Isolate::Current(), buffer, size),
+MacroAssembler::MacroAssembler(Isolate* arg_isolate, void* buffer, int size)
+    : Assembler(arg_isolate, buffer, size),
       generating_stub_(false),
-      allow_stub_calls_(true),
-      code_object_(isolate()->heap()->undefined_value()) {
+      allow_stub_calls_(true) {
+  if (isolate() != NULL) {
+    code_object_ = Handle<Object>(isolate()->heap()->undefined_value(),
+                                  isolate());
+  }
 }
 
 
@@ -2896,7 +2899,7 @@ CodePatcher::CodePatcher(byte* address, int instructions)
     : address_(address),
       instructions_(instructions),
       size_(instructions * Assembler::kInstrSize),
-      masm_(address, size_ + Assembler::kGap) {
+      masm_(Isolate::Current(), address, size_ + Assembler::kGap) {
   // Create a new macro assembler pointing to the address of the code to patch.
   // The size is adjusted with kGap on order for the assembler to generate size
   // bytes of instructions without failing with buffer size constraints.