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

src/code-stubs.cc

Index: src/code-stubs.cc
diff --git a/src/code-stubs.cc b/src/code-stubs.cc
index 5383339510e1d338258a8a5220007c7ac0309db5..ace4af42a9e0797723a242e8873c8ab9d7825a50 100644
--- a/src/code-stubs.cc
+++ b/src/code-stubs.cc
@@ -136,7 +136,7 @@ Handle<Code> CodeStub::GetCode(Isolate* isolate) {
   if (UseSpecialCache()
       ? FindCodeInSpecialCache(&code, isolate)
       : FindCodeInCache(&code, isolate)) {
-    ASSERT(IsPregenerated() == code->is_pregenerated());
+    ASSERT(IsPregenerated(isolate) == code->is_pregenerated());
     return Handle<Code>(code);
   }