Hack to support variables of anonymous enum types

Declare the variable as int as this is how variables of enum types are stored
(although this would have to be revised when support for C++11 base enum type
is added) and, although ugly, this at least allows the generated code to
compile.

This fixes some (but not all yet) errors in the "enums" and "cpp_enum" unit
tests.

Examples/test-suite/c/enums_runme.c

@@ -1,8 +1,9 @@
-#include <stdio.h>
+#include <assert.h>
 
 #include "enums/enums_wrap.h"
 
 int main() {
+  assert(GlobalInstance == globalinstance1);
   bar2(1);
   bar3(1);
   bar1(1);