Bug 1280930 - pushJoinReg must push void values, not ignore them. r=bbouvier

--HG--
extra : rebase_source : 4bb6d9ef25d4593d447a76ecf2eddc7cc62ae146
extra : histedit_source : 76c65549c44d63e2d589dd1138f8e77c1ad263df

js/src/asmjs/WasmBaselineCompile.cpp

@@ -1485,6 +1485,7 @@ class BaseCompiler
     void pushJoinReg(AnyReg r) {
         switch (r.tag) {
           case AnyReg::NONE:
+            pushVoid();
             break;
           case AnyReg::I32:
             pushI32(r.i32());