UPSTREAM: gnat.adc: Do not generate assertion code for Refined_Post

Ada usually does lots of type and contract checking during runtime. As
this produces overhead and there is nobody to tell when we run into an
exception, we disable code generation for those checks. Now disable it
for `Refined_Post` too, which was just missed earlier.

BUG=None
BRANCH=None
TEST=None

Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/16945
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

Change-Id: I67ca754f830e387efee3930e86929eb494bfaf03
Reviewed-on: https://chromium-review.googlesource.com/406943
Commit-Ready: Furquan Shaikh <furquan@chromium.org>
Tested-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

gnat.adc

@@ -35,6 +35,7 @@ pragma Restrictions (Static_Storage_Size);
 pragma Assertion_Policy
   (Statement_Assertions => Disable,
    Pre                  => Disable,
-   Post                 => Disable);
+   Post                 => Disable,
+   Refined_Post         => Disable);
 pragma Overflow_Mode (General => Strict, Assertions => Eliminated);
 pragma SPARK_Mode (On);