Merge 10601,10602,10616,10625,10647 from the bleeding edge to the 3.8 branch.

src/mksnapshot.cc

Index: src/mksnapshot.cc
===================================================================
--- src/mksnapshot.cc	(revision 10927)
+++ src/mksnapshot.cc	(working copy)
@@ -312,7 +312,7 @@
   }
   // If we don't do this then we end up with a stray root pointing at the
   // context even after we have disposed of the context.
-  HEAP->CollectAllGarbage(i::Heap::kNoGCFlags);
+  HEAP->CollectAllGarbage(i::Heap::kNoGCFlags, "mksnapshot");
   i::Object* raw_context = *(v8::Utils::OpenHandle(*context));
   context.Dispose();
   CppByteSink sink(argv[1]);