rocmPackages_5.llvm: use gcc12Stdenv if stdenv.cc.cc.isGNU>=13

pkgs/development/rocm-modules/5/llvm/base.nix

@@ -1,5 +1,6 @@
 { lib
 , stdenv
+, gcc12Stdenv
 , fetchFromGitHub
 , rocmUpdateScript
 , pkg-config
@@ -44,6 +45,13 @@
 , isBroken ? false
 }:
 
+let stdenv' = stdenv; in
+let stdenv =
+      if stdenv'.cc.cc.isGNU or false && lib.versionAtLeast stdenv'.cc.cc.version "13.0"
+      then gcc12Stdenv
+      else stdenv';
+in
+
 let
   llvmNativeTarget =
     if stdenv.isx86_64 then "X86"

pkgs/development/rocm-modules/5/llvm/stage-2/rstdenv.nix

@@ -12,6 +12,7 @@ overrideCC stdenv (wrapCCWith rec {
   inherit bintools;
   libcxx = runtimes;
   cc = clang-unwrapped;
+  gccForLibs = stdenv.cc.cc;
 
   extraPackages = [
     llvm