fixing decl_initializer() for size_only: don't eat ')'

fixing decl_initializer() for size_only: don't eat ')'
a test program:

    struct { int c[1]; } s1[] = { (int)0       }; /* OK */
    struct { int c[1]; } s2[] = { { ((int)0) } }; /* OK */
    struct { int c[1]; } s3[] = { 0            }; /* OK */
    struct { int c[1]; } sx[] = { ((int)0)     }; /* error: ')' expected (got "}") */
    int main() { return 0; }