[Ada] ACATS 4.1K - B452001 - No errors detected

[Ada] ACATS 4.1K - B452001 - No errors detected

2020-06-16  Arnaud Charlet  <charlet@adacore.com>

gcc/ada/

	* sem_ch4.adb (Analyze_Membership_Op): Reset entity of equality
	nodes for membership tests with singletons.
	(Analyze_User_Defined_Binary_Op): Always perform the analysis
	since nodes coming from the expander also may refer to non
	standard operators as part of membership expansion.
	* exp_ch4.adb (Expand_Set_Membership.Make_Cond): Reset entity of
	equality node.
	* sem_type.ads: Fix typo in comment.