* config/tc-sparc.c: (lookup_arch,init_default_arch): New functions.

	* config/tc-sparc.c: (lookup_arch,init_default_arch): New functions.
	(default_arch,default_init_p,sparc_arch_table): New static locals.
	(sparc_arch_size): New static local.
	(max_architecture): Initialize in init_default_arch.
	(md_parse_options): Call init_default_arch if necessary.
	Rewrite -xarch/-A processing.
	(md_show_usage): Print -A values from sparc_arch_table.
	(md_begin): Call init_default_arch if necessary.
	(sparc_md_end): Handle both 32 and 64 bit environments.
	* config/tc-sparc.h (TARGET_FORMAT): Likewise.
	* acconfig.h (SPARC_V9,SPARC_ARCH64): Delete.
	(DEFAULT_ARCH): Add.
	* config.in: Regenerate.
	* configure.in (sparc): Default DEFAULT_ARCH based on target cpu.
	(SPARC_V9,SPARC_ARCH64): Delete.
	* configure: Regenerate.
	* config/vms-conf.h (SPARC_V9,SPARC_ARCH64): Delete.