Fix x86/56337 : 1<<28 alignment is broken

Fix x86/56337 : 1<<28 alignment is broken

The problem here is the x86_64 back-end uses a signed integer
for alignment and then divides by BITS_PER_UNIT so if we had
INT_MIN (which is what 1<<28*8 is), we would get the wrong result.

This fixes the problem by using unsigned for the argument to
x86_output_aligned_bss and x86_output_aligned_bss.

OK? Bootstrapped and tested on x86_64-linux-gnu.

gcc/ChangeLog:

	PR target/56337
	* config/i386/i386-protos.h (x86_output_aligned_bss):
	Change align argument to unsigned type.
	(x86_elf_aligned_decl_common): Likewise.
	* config/i386/i386.c (x86_elf_aligned_decl_common): Likewise.
	(x86_output_aligned_bss): Likewise.