valgrind: remove Darwin‐related dead code

This has been broken on Darwin since 2020 and depends on deprecated
stubs. Best to remove it until someone figures out how to get it
working again than spend effort tidying up dead code.

pkgs/development/tools/analysis/valgrind/default.nix

···
   autoreconfHook,
   perl,
   gdb,
-  cctools,
-  xnu,
-  bootstrap_cmds,
   writeScript,
 }:
 
···
 
   # GDB is needed to provide a sane default for `--db-command'.
   # Perl is needed for `callgrind_{annotate,control}'.
-  buildInputs =
-    [
-      gdb
-      perl
-    ]
-    ++ lib.optionals (stdenv.hostPlatform.isDarwin) [
-      bootstrap_cmds
-      xnu
-    ];
+  buildInputs = [
+    gdb
+    perl
+  ];
 
   # Perl is also a native build input.
   nativeBuildInputs = [
···
   enableParallelBuilding = true;
   separateDebugInfo = stdenv.hostPlatform.isLinux;
 
-  preConfigure =
-    lib.optionalString stdenv.hostPlatform.isFreeBSD ''
-      substituteInPlace configure --replace-fail '`uname -r`' ${stdenv.cc.libc.version}-
-    ''
-    + lib.optionalString stdenv.hostPlatform.isDarwin (
-      let
-        OSRELEASE = ''
-          $(awk -F '"' '/#define OSRELEASE/{ print $2 }' \
-          <${xnu}/Library/Frameworks/Kernel.framework/Headers/libkern/version.h)'';
-      in
-      ''
-        echo "Don't derive our xnu version using uname -r."
-        substituteInPlace configure --replace "uname -r" "echo ${OSRELEASE}"
+  preConfigure = lib.optionalString stdenv.hostPlatform.isFreeBSD ''
+    substituteInPlace configure --replace-fail '`uname -r`' ${stdenv.cc.libc.version}-
+  '';
 
-        # Apple's GCC doesn't recognize `-arch' (as of version 4.2.1, build 5666).
-        echo "getting rid of the \`-arch' GCC option..."
-        find -name Makefile\* -exec \
-          sed -i {} -e's/DARWIN\(.*\)-arch [^ ]\+/DARWIN\1/g' \;
-
-        sed -i coregrind/link_tool_exe_darwin.in \
-            -e 's/^my \$archstr = .*/my $archstr = "x86_64";/g'
-
-        substituteInPlace coregrind/m_debuginfo/readmacho.c \
-           --replace /usr/bin/dsymutil ${stdenv.cc.bintools.bintools}/bin/dsymutil
-
-        echo "substitute hardcoded /usr/bin/ld with ${cctools}/bin/ld"
-        substituteInPlace coregrind/link_tool_exe_darwin.in \
-          --replace /usr/bin/ld ${cctools}/bin/ld
-      ''
-    );
-
-  configureFlags =
-    lib.optional stdenv.hostPlatform.isx86_64 "--enable-only64bit"
-    ++ lib.optional stdenv.hostPlatform.isDarwin "--with-xcodedir=${xnu}/include";
+  configureFlags = lib.optional stdenv.hostPlatform.isx86_64 "--enable-only64bit";
 
   doCheck = true;
 
···
         darwin ++ freebsd ++ illumos ++ linux
       );
     badPlatforms = [ lib.systems.inspect.platformPatterns.isStatic ];
-    broken = stdenv.hostPlatform.isDarwin; # https://hydra.nixos.org/build/128521440/nixlog/2
+    # See: <https://hydra.nixos.org/build/128521440/nixlog/2>
+    #
+    # Darwin‐specific derivation logic has been removed, check the
+    # history if you want to fix this.
+    broken = stdenv.hostPlatform.isDarwin;
   };
 }

pkgs/top-level/all-packages.nix

···
     jdk = jdk11;
   };
 
-  valgrind = callPackage ../development/tools/analysis/valgrind {
-    inherit (buildPackages.darwin) xnu bootstrap_cmds;
-  };
+  valgrind = callPackage ../development/tools/analysis/valgrind { };
   valgrind-light = (res.valgrind.override { gdb = null; }).overrideAttrs (oldAttrs: {
     meta = oldAttrs.meta // {
       description = "${oldAttrs.meta.description} (without GDB)";