contrib/compiler: remove dead tests

contrib/ccan/compiler/test/compile_fail-printf.c

-#include <ccan/compiler/compiler.h>
-
-static void PRINTF_FMT(2,3) my_printf(int x, const char *fmt, ...)
-{
-}
-
-int main(int argc, char *argv[])
-{
-	unsigned int i = 0;
-
-	my_printf(1, "Not a pointer "
-#ifdef FAIL
-		  "%p",
-#if !HAVE_ATTRIBUTE_PRINTF
-#error "Unfortunately we don't fail if !HAVE_ATTRIBUTE_PRINTF."
-#endif
-#else
-		  "%i",
-#endif
-		  i);
-	return 0;
-}

contrib/ccan/compiler/test/run-is_compile_constant.c

-#include <ccan/compiler/compiler.h>
-#include <ccan/tap/tap.h>
-
-int main(int argc, char *argv[])
-{
-	plan_tests(2);
-
-	ok1(!IS_COMPILE_CONSTANT(argc));
-#if HAVE_BUILTIN_CONSTANT_P
-	ok1(IS_COMPILE_CONSTANT(7));
-#else
-	pass("If !HAVE_BUILTIN_CONSTANT_P, IS_COMPILE_CONSTANT always false");
-#endif
-	return exit_status();
-}