Bug 1172076 - Switch compartment before computing recover instruction results. r=jandem

js/src/jit/JitFrames.cpp

@@ -2183,6 +2183,8 @@ SnapshotIterator::initInstructionResults(MaybeReadFallback& fallback)
     JitFrameLayout* fp = fallback.frame->jsFrame();
     RInstructionResults* results = fallback.activation->maybeIonFrameRecovery(fp);
     if (!results) {
+        AutoCompartment ac(cx, fallback.frame->script()->compartment());
+
         // We do not have the result yet, which means that an observable stack
         // slot is requested.  As we do not want to bailout every time for the
         // same reason, we need to recompile without optimizing away the