oneDNN: use SSE 4.1 when running tests

Feature detection may fail, leading to illegal instructions when
running tests. Cap tests at SSE 4.1, which is supported on many
Intel/AMD CPUs since 2006/2007.

pkgs/development/libraries/oneDNN/default.nix

@@ -24,6 +24,9 @@ stdenv.mkDerivation rec {
   preCheck = ''
     export LD_LIBRARY_PATH=$LD_LIBRARY_PATH''${LD_LIBRARY_PATH:+:}$PWD/src
     export DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH''${DYLD_LIBRARY_PATH:+:}$PWD/src
+  '' + lib.optionalString stdenv.isx86_64 ''
+    # Use baseline SIMD in case CPU features get misdetected.
+    export DNNL_MAX_CPU_ISA=SSE41
   '';
 
   # The cmake install gets tripped up and installs a nix tree into $out, in