2017-04-25  Hristian Kirtchev  <kirtchev@adacore.com>

	* comperr.adb (Compiler_Abort): Add a pair of pragma Warnings
	On/Off to defend against a spurious warning in conditional
	compilation.
	* exp_ch4.adb (Rewrite_Comparison): Reimplemented.
	* namet.adb (Finalize): Add a pair of pragma Warnings On/Off to
	defend against a spurious warning in conditional compilation.
	* output.adb Add a pair of pragma Warnings On/Off to defend
	against a spurious warning in conditional compilation.
	* sem_eval.adb (Eval_Relational_Op): Major code clean up.
	(Fold_General_Op): New routine.
	(Fold_Static_Real_Op): New routine.
	(Test_Comparison): New routine.
	* sem_eval.ads (Test_Comparison): New routine.
	* sem_warn.adb (Is_Attribute_Constant_Comparison): New routine.
	(Warn_On_Constant_Valid_Condition): New routine.
	(Warn_On_Known_Condition): Use Is_Attribute_Constant_Comparison
	to detect a specific case.
	* sem_warn.adb (Warn_On_Constant_Valid_Condition): New routine.
	* urealp.adb (Tree_Read): Add a pair of pragma Warnings On/Off
	to defend against a spurious warning in conditional compilation.
	(Tree_Write): Add a pair of pragma Warnings On/Off to defend
	against a spurious warning in conditional compilation.
	* usage.adb Add a pair of pragma Warnings On/Off to defend
	against a spurious warning in conditional compilation.

2017-04-25  Arnaud Charlet  <charlet@adacore.com>

	* sinfo.ads, sem_ch13.adb: Update comment.

From-SVN: r247224