[RFC] use symbol_ref flags for rs6000

[David Edelsohn]

	Richard's AIX xcoff suggestions look correct.

	Your patch changes current_file_function_operand(), which is the
only place that tests SYMBOL_REF_FLAG.  If the flag no longer is tested
and something is wrong for AIX, things will break whether or not the xcoff
code setting the flag remains.

	The test for SYMBOL_REF_LOCAL_P in current_file_function_operand()
should be sufficient.

Richard> The predicate that they are checking is 

Richard> SYMBOL_REF_LOCAL_P (x) && SYMBOL_REF_FUNCTION_P (x)

Richard> And given that this is used only in calls, you may or may not
Richard> need to check SYMBOL_REF_FUNCTION_P at all.

	You might want to test SYMBOL_REF_FUNCTION_P (x) in
current_file_function_operand() bracketed by ENABLE_CHECKING.  It
essentially is an assertion.

David