[Ada] improve error message on abnormal return

[Arnaud Charlet <charlet at adacore dot com>]

Tested on i686-linux, committed on HEAD

The old message in this case said
warning: "raise" statement is abnormal return (RM 6.4.1(17))
Well that was not quite true, since in rather unusual cases,
the exception could be handled locally. To make this false
positive warning a bit less "wrong", the message now says:
test_out_par_1.adb:8:09: warning: "raise" statement may result
 in abnormal return (RM 6.4.1(17)).
The following test program demonstrates the new message
procedure Q (X : in out Integer) is
begin
   X := 5;
   raise Constraint_Error;
exception
   when others => null;
end;

2005-03-29  Robert Dewar  <dewar@adacore.com>

	* sem_ch11.adb (Analyze_Raise_Statement): Change message for warning
	on param update.

Attachment: difs.19
Description: Text document