testsuite/52641: Fix fallout from sloppy tests.

gcc/testsuite/
	PR testsuite/52641
	* gcc.dg/memchr-3.c [avr]: Anticipate -Wbuiltin-declaration-mismatch.
	* gcc.dg/pr103207.c: Use __INT32_TYPE__ instead of int.
	* gcc.dg/pr103451.c [void* != long]: Anticipate -Wpointer-to-int-cast.
	* gcc.dg/pr110496.c [void* != long]: Anticipate -Wint-to-pointer-cast.
	* gcc.dg/pr109977.c: Use __SIZEOF_DOUBLE__ instead of 8.
	* gcc.dg/pr110506-2.c: Use __UINT32_TYPE__ for uint32_t.
	* gcc.dg/pr110582.c: Require int32plus.
	* gcc.dg/pr111039.c: [sizeof(int) < 4]: Use __INT32_TYPE__.
	* gcc.dg/pr111599.c: Same.
	* gcc.dg/builtin-dynamic-object-size-0.c: Require size20plus.
	* gcc.dg/builtin-object-size-1.c [avr]: Skip tests with strndup.
	* gcc.dg/builtin-object-size-2.c: Same.
	* gcc.dg/builtin-object-size-3.c: Same.
	* gcc.dg/builtin-object-size-4.c: Same.
	* gcc.dg/pr111070.c: Use __UINTPTR_TYPE__ instead of unsigned long.
	* gcc.dg/debug/btf/btf-pr106773.c: Same.
	* gcc.dg/debug/btf/btf-bitfields-2.c: [sizeof(int) < 4]: Use
	__UINT32_TYPE__.