Remove default isolate usage from almost all tests

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index b826ec596abaa1225b66f4b8ff926e5726b6ddbe..b7ea209b295e6526d97675fef48da983fb7d8341 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -497,6 +497,7 @@ class Isolate {
 
   bool IsDefaultIsolate() const { return this == default_isolate_; }
 
+  static void SetCrashIfDefaultIsolateInitialized();
   // Ensures that process-wide resources and the default isolate have been
   // allocated. It is only necessary to call this method in rare cases, for
   // example if you are using V8 from within the body of a static initializer.