Bug 856877 - Initialize JSRuntime::interrupt. r=wmccloskey.

--HG--
extra : rebase_source : 793f3357ea5850ecc282c7c150a8bdf71b5b78f9

js/src/jsapi.cpp

@@ -718,6 +718,7 @@ PerThreadData::~PerThreadData()
 
 JSRuntime::JSRuntime(JSUseHelperThreads useHelperThreads)
   : mainThread(this),
+    interrupt(0),
     atomsCompartment(NULL),
     systemZone(NULL),
     numCompartments(0),