config.gcc (alpha*-dec-osf[45]*): Set use_gcc_stdint.

	gcc:
	* config.gcc (alpha*-dec-osf[45]*): Set use_gcc_stdint.
	* config/alpha/osf.h (SIG_ATOMIC_TYPE): Define.
	(INT8_TYPE, INT16_TYPE, INT32_TYPE, INT64_TYPE): Define.
	(UINT8_TYPE, UINT16_TYPE, UINT32_TYPE, UINT64_TYPE): Define.
	(INT_LEAST8_TYPE, INT_LEAST16_TYPE, INT_LEAST32_TYPE,
	(INT_LEAST64_TYPE): Define.
	(UINT_LEAST8_TYPE, UINT_LEAST16_TYPE, UINT_LEAST32_TYPE,
	UINT_LEAST64_TYPE): Define.
	(INT_FAST8_TYPE, INT_FAST16_TYPE, INT_FAST32_TYPE,
	INT_FAST64_TYPE): Define.
	(UINT_FAST8_TYPE, UINT_FAST16_TYPE, UINT_FAST32_TYPE,
	UINT_FAST64_TYPE): Define.
	(INTPTR_TYPE, UINTPTR_TYPE): Define.

	gcc/testsuite:
	* gcc.dg/c99-stdint-6.c: Set dg-options for alpha*-dec-osf5*.
	Wrap *int_least*_t tests in !NO_LEAST_TYPES.
	Wrap *intmax_t tests in !NO_MAX_TYPES.

From-SVN: r154373