Adds storage_reference.sol syntax test

test/libsolidity/syntaxTests/inlineAssembly/storage_reference.sol

@@ -0,0 +1,11 @@
+contract C {
+    uint[] x;
+    function() { 
+        uint[] storage y = x;
+        assembly {
+            pop(y)
+        }
+    }
+}
+// ----
+// TypeError: (110-111): You have to use the _slot or _offset suffix to access storage reference variables.