More fixes to allow 64-bit ppc assembler generate 32-bit code

[Alan Modra]

On Thu, Oct 04, 2001 at 06:45:45PM +0930, Alan Modra wrote:
> gas/ChangeLog
> 	* config/tc-ppc.c (PPC_HA, PPC_HIGHERA, PPC_HIGHESTA): Simplify.
> 	(ppc_size): Select PPC_OPCODE_64 if 64 bit.
> 	(md_begin): Don't set ppc_size here.
> 	(ppc_target_format): Test ppc_size as well as BFD_DEFAULT_TARGET_SIZE.
> 	(md_shortopts): Constify.
> 	(md_longopts): Likewise.
> 	(md_longopts_size): Likewise.
> 	(ppc_elf_suffix): Only allow 64-bit relocs when ppc_size specifies
> 	64-bit opcodes.
> 	(ppc_machine): Explain why this function is a nop.

Committed.