Upgrade SLOTHY to the HEAD of its main branch, as of 13th June 2025.

This incorporates micro-arch models for all the instructions required by
mlkem-native on the Neoverse-N1 core.

Signed-off-by: Rod Chapman <rodchap@amazon.com>

Signed-off-by: Matthias J. Kannwischer <matthias@kannwischer.eu>

Author: rod-chapman

nix/slothy/default.nix

@@ -5,6 +5,7 @@
 , python3
 , pkgs
 , llvm
+, gcc
 }:
 
 let
@@ -16,13 +17,12 @@ let
 in
 stdenvNoCC.mkDerivation rec {
   pname = "slothy-cli";
-  version = "5fafd8048c3ba7c5924cbd2e16e77040fa847447";
-
+  version = "915c224166207ce07b31152194305c3b6687d09b";
   src = fetchFromGitHub {
     owner = "slothy-optimizer";
     repo = "slothy";
     rev = version;
-    sha256 = "sha256-3X8Z4Wgb+sGrDYTffBrG4hF3UAIVwab60XMiijtZlIY";
+    sha256 = "sha256-ebZjm+nhmML/+DZF78eN1ezoxbv5Rrc5kWsh0Ycww4U=";
   };
 
   nativeBuildInputs = [ pkgs.makeWrapper ];
@@ -40,7 +40,7 @@ stdenvNoCC.mkDerivation rec {
 
   dontStrip = true;
   noAuditTmpdir = true;
-  propagatedBuildInputs = [ pythonEnv llvm ];
+  propagatedBuildInputs = [ pythonEnv llvm gcc ];
 
   meta = {
     description = "Slothy: assembly-level superoptimizer";