[Ada] Adapt CodePeer analysis of GNAT to changes in dependencies

[Pierre-Marie de Rodat via Gcc-patches]

New dependencies in s-imagei are causing issues for CodePeer analysis
of GNAT source and libs. Updating the setup.

Tested on x86_64-pc-linux-gnu, committed on trunk

gcc/ada/

        * libgnat/s-imagef.adb: Justify false message from CodePeer.
diff --git a/gcc/ada/libgnat/s-imagef.adb b/gcc/ada/libgnat/s-imagef.adb
--- a/gcc/ada/libgnat/s-imagef.adb
+++ b/gcc/ada/libgnat/s-imagef.adb
@@ -433,6 +433,8 @@ package body System.Image_F is
          Digs (1 .. 2) := " 0";
          Ndigs := 2;
       end if;
+      pragma Annotate (CodePeer, False_Positive, "test always true",
+                       "no digits were output for zero");
 
       Set_Decimal_Digits (Digs, Ndigs, S, P, Scale, Fore, Aft, Exp);
    end Set_Image_Fixed;