Fix test/build failures (win64 compile warning, isolate test parallel compilation failure, gcmole i…

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 57854b81415fc356578dcf40b7f5d4c223717d02..f1b21d7959a52659af295cfc1078f96fc6d82927 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -1860,7 +1860,7 @@ HValue* HGraphBuilder::JSArrayBuilder::EmitMapCode(HValue* context) {
       HGlobalObject(context));
   HInstruction* native_context = AddInstruction(new(zone())
       HLoadNamedField(global_object, true, GlobalObject::kNativeContextOffset));
-  size_t offset = Context::kHeaderSize +
+  int offset = Context::kHeaderSize +
       kPointerSize * Context::JS_ARRAY_MAPS_INDEX;
   HInstruction* map_array = AddInstruction(new(zone())
       HLoadNamedField(native_context, true, offset));