[bootstrapper] Eliminate all GetIsolates

Removes all explicit calls to GetIsolate() in runtime/ by passing it
through calling functions.

Bug: v8:7786
Change-Id: I6485827ea3ef9b215ca487b1f823c9f585f31f98
Reviewed-on: https://chromium-review.googlesource.com/1080747Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53458}

src/bootstrapper.h

@@ -31,7 +31,8 @@ class SourceCodeCache final BASE_EMBEDDED {
 
   bool Lookup(Vector<const char> name, Handle<SharedFunctionInfo>* handle);
 
-  void Add(Vector<const char> name, Handle<SharedFunctionInfo> shared);
+  void Add(Isolate* isolate, Vector<const char> name,
+           Handle<SharedFunctionInfo> shared);
 
  private:
   Script::Type type_;