Bug 1309160 - prevent null pointer dereference when calling TraceRootRange/ r=jandem

MozReview-Commit-ID: EhcmRbtyFVN

--HG--
extra : rebase_source : 9166647b3e502eb8686946e9592db4167a00c16c

js/src/jit/RematerializedFrame.h

@@ -169,6 +169,7 @@ class RematerializedFrame
     }
     JSFunction* callee() const {
         MOZ_ASSERT(isFunctionFrame());
+        MOZ_ASSERT(callee_);
         return callee_;
     }
     Value calleev() const {