[COMMITTED] ada: Adjust number of errors when removing warning in dead code

["Marc Poulhiès" <poulhies@adacore.com>]

From: Piotr Trojanek <trojanek@adacore.com>

When a warning about a runtime exception is emitted for a code in
generic instance, we add continuation warnings "in instantiation ..."
and only the original message increase the total number of errors.

When removing these messages, e.g. after detecting that the code inside
generic instance is dead, we must decrease the total number of errors,
as otherwise the compiler exit status might stop gnatmake or gprbuild.

gcc/ada/

	* errout.adb (To_Be_Removed): Decrease total number of errors when
	removing a warning that has been escalated into error.
	* erroutc.adb (dmsg): Print Warn_Runtime_Raise flag.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/ada/errout.adb  | 11 +++++++++++
 gcc/ada/erroutc.adb | 35 ++++++++++++++++++-----------------
 2 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/gcc/ada/errout.adb b/gcc/ada/errout.adb
index afa30674fa3..b30e8b51d15 100644
--- a/gcc/ada/errout.adb
+++ b/gcc/ada/errout.adb
@@ -3351,6 +3351,17 @@ package body Errout is
                   Warning_Info_Messages := Warning_Info_Messages - 1;
                end if;
 
+               --  When warning about a runtime exception has been escalated
+               --  into error, the starting message has increased the total
+               --  errors counter, so here we decrease this counter.
+
+               if Errors.Table (E).Warn_Runtime_Raise
+                 and then not Errors.Table (E).Msg_Cont
+                 and then Warning_Mode = Treat_Run_Time_Warnings_As_Errors
+               then
+                  Total_Errors_Detected := Total_Errors_Detected - 1;
+               end if;
+
                return True;
 
             --  No removal required
diff --git a/gcc/ada/erroutc.adb b/gcc/ada/erroutc.adb
index 7766c972730..d40c668be8a 100644
--- a/gcc/ada/erroutc.adb
+++ b/gcc/ada/erroutc.adb
@@ -312,32 +312,33 @@ package body Erroutc is
 
    begin
       w ("Dumping error message, Id = ", Int (Id));
-      w ("  Text     = ", E.Text.all);
-      w ("  Next     = ", Int (E.Next));
-      w ("  Prev     = ", Int (E.Prev));
-      w ("  Sfile    = ", Int (E.Sfile));
+      w ("  Text               = ", E.Text.all);
+      w ("  Next               = ", Int (E.Next));
+      w ("  Prev               = ", Int (E.Prev));
+      w ("  Sfile              = ", Int (E.Sfile));
 
       Write_Str
-        ("  Sptr     = ");
+        ("  Sptr               = ");
       Write_Location (E.Sptr.Ptr);  --  ??? Do not write the full span for now
       Write_Eol;
 
       Write_Str
-        ("  Optr     = ");
+        ("  Optr               = ");
       Write_Location (E.Optr.Ptr);
       Write_Eol;
 
-      w ("  Line     = ", Int (E.Line));
-      w ("  Col      = ", Int (E.Col));
-      w ("  Warn     = ", E.Warn);
-      w ("  Warn_Err = ", E.Warn_Err);
-      w ("  Warn_Chr = '" & E.Warn_Chr & ''');
-      w ("  Style    = ", E.Style);
-      w ("  Serious  = ", E.Serious);
-      w ("  Uncond   = ", E.Uncond);
-      w ("  Msg_Cont = ", E.Msg_Cont);
-      w ("  Deleted  = ", E.Deleted);
-      w ("  Node     = ", Int (E.Node));
+      w ("  Line               = ", Int (E.Line));
+      w ("  Col                = ", Int (E.Col));
+      w ("  Warn               = ", E.Warn);
+      w ("  Warn_Err           = ", E.Warn_Err);
+      w ("  Warn_Runtime_Raise = ", E.Warn_Runtime_Raise);
+      w ("  Warn_Chr           = '" & E.Warn_Chr & ''');
+      w ("  Style              = ", E.Style);
+      w ("  Serious            = ", E.Serious);
+      w ("  Uncond             = ", E.Uncond);
+      w ("  Msg_Cont           = ", E.Msg_Cont);
+      w ("  Deleted            = ", E.Deleted);
+      w ("  Node               = ", Int (E.Node));
 
       Write_Eol;
    end dmsg;
-- 
2.34.1