ref: b0561e50ec063be50dcd76fb3c1f6cd31dbd75fe
dir: /tests/cc/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;
}