Rename our max_align_t to sxe_max_align_t

Rename our max_align_t to sxe_max_align_t

	This is needed because newer compilers now ship with this
	symbol.

	* src/sxe-utils.h: Rename max_align_t to sxe_max_align_t
	* src/dumper.c (pdump_get_entry_list): Use sxe_max_align_t
	(pdump_scan_by_alignment): Ditto.
	(pdump): Ditto.
	* src/opaque.c (aligned_sizeof_opaque): Ditto.
	* src/opaque.h (Lisp_Opaque): Ditto.
	* src/specifier.h (Lisp_Specifier): Ditto.

Signed-off-by: Nelson Ferreira <nelson.ferreira@ieee.org>