ref: ca543c97d5f35334bc9784a3b5c7c5a8fe7a8f8a
dir: /tests/execute/0152-cat.c/
#define CAT(x,y) x ## y
#define XCAT(x,y) CAT(x,y)
#define FOO foo
#define BAR bar
int
main(void)
{
	int foo, bar, foobar;
	CAT(foo,bar) = foo + bar;
	XCAT(FOO,BAR) = foo + bar;
	return 0;
}