[Ada] Give missing error on ambiguous operand of equality operator

[Ada] Give missing error on ambiguous operand of equality operator

When the code responsible for giving errors on ambiguous operands of
comparison and equality operators was moved from the 1st phase (analysis)
to the 2nd phase (resolution) of semantic processing, it was incorrectly
restricted to the operator case, which was valid during the 1st phase but
is not during the 2nd phase.

gcc/ada/

	* sem_res.adb (Resolve_Comparison_Op): Deal with ambiguous operands
	in all cases.
	(Resolve_Equality_Op): Likewise, except for the case of the implicit
	inequality operator created for a user-defined operator that is not
	an intrinsic subprogram.