firefox: limit disable-elf-hack to arm, x86{,_64}

This is a follow up to #106617 which brought LTO support but broke the
AArch64 Firefox builds.

pkgs/applications/networking/browsers/firefox/common.nix

@@ -296,10 +296,9 @@ buildStdenv.mkDerivation ({
   #   https://bugzilla.mozilla.org/show_bug.cgi?id=1538724
   # elf-hack is broken when using clang+lld:
   #   https://bugzilla.mozilla.org/show_bug.cgi?id=1482204
-  ++ lib.optionals ltoSupport [
-    "--enable-lto"
-    "--disable-elf-hack"
-  ] ++ lib.optional (ltoSupport && !buildStdenv.isDarwin) "--enable-linker=lld"
+  ++ lib.optional ltoSupport "--enable-lto"
+  ++ lib.optional (ltoSupport && (buildStdenv.isAarch32 || buildStdenv.isi686 || buildStdenv.isx86_64)) "--disable-elf-hack"
+  ++ lib.optional (ltoSupport && !buildStdenv.isDarwin) "--enable-linker=lld"
 
   ++ flag alsaSupport "alsa"
   ++ flag pulseaudioSupport "pulseaudio"