feat(libjpeg-turbo): add patch for libjpeg-turbo with custom cmakeFlags

common/optional/x86-64-v3/patches/default.nix

@@ -2,6 +2,7 @@ _final: prev:
 (import ./abseil { inherit prev; })
 // {
   gnutls = import ./gnutls { inherit (prev) gnutls; };
+  libjpeg_turbo = import ./libjpeg-turbo { inherit (prev) lib libjpeg_turbo stdenv; };
   prometheus = import ./prometheus { inherit (prev) prometheus; };
   zopfli = import ./zopfli { inherit (prev) zopfli; };
 

common/optional/x86-64-v3/patches/libjpeg-turbo/default.nix

@@ -0,0 +1,15 @@
+{
+  lib,
+  libjpeg_turbo,
+  stdenv,
+}:
+libjpeg_turbo.overrideAttrs (old: {
+  # This overlay also reaches pkgsi686Linux. Its 12-bit floating-point code
+  # uses x87, while x86-64-v3 uses FMA. Keep the tests enabled for both.
+  cmakeFlags =
+    (old.cmakeFlags or [ ])
+    ++ lib.optional (
+      stdenv.hostPlatform.isx86_64 && (stdenv.hostPlatform.gcc.arch or null) == "x86-64-v3"
+    ) "-DFLOATTEST12=fp-contract"
+    ++ lib.optional stdenv.hostPlatform.isi686 "-DFLOATTEST12=387";
+})