[amdgcn] Remove dependency on stdint.h in libgcc

2020-01-10  Kwok Cheung Yeung  <kcy@codesourcery.com>

	libgcc/
	* config/gcn/atomic.c: Remove include of stdint.h.
	(__sync_val_compare_and_swap_##SIZE): Replace uintptr_t with
	__UINTPTR_TYPE__.

From-SVN: r280152