glibc: suppress warning about IEEE-standard long double

pkgs/development/libraries/glibc/default.nix

@@ -63,6 +63,13 @@ in
             # Same for musl: https://github.com/NixOS/nixpkgs/issues/78805
             "-Wno-error=missing-attributes"
           ])
+          (lib.optionals (stdenv.hostPlatform.isPower64) [
+            # Do not complain about the Processor Specific ABI (i.e. the
+            # choice to use IEEE-standard `long double`).  We pass this
+            # flag in order to mute a `-Werror=psabi` passed by glibc;
+            # hopefully future glibc releases will not pass that flag.
+            "-Wno-error=psabi"
+          ])
         ]);
     };