Return Object* instead of MaybeObject* from runtime calls.

src/execution.h

Index: src/execution.h
diff --git a/src/execution.h b/src/execution.h
index 4510fd13ec07e9379ee675271d280b6b05a8f111..d4838519408124b16f55420ddd2de1ce5a4d68ff 100644
--- a/src/execution.h
+++ b/src/execution.h
@@ -125,8 +125,7 @@ class Execution V8_FINAL : public AllStatic {
 
   // If the stack guard is triggered, but it is not an actual
   // stack overflow, then handle the interruption accordingly.
-  MUST_USE_RESULT static MaybeObject* HandleStackGuardInterrupt(
-      Isolate* isolate);
+  static Object* HandleStackGuardInterrupt(Isolate* isolate);
 
   // Get a function delegate (or undefined) for the given non-function
   // object. Used for support calling objects as functions.