Merge: glibc: allow easier overriding of linux headers package (#413735)

pkgs/development/libraries/glibc/common.nix

···
 
   // (removeAttrs args [
     "withLinuxHeaders"
+    "linuxHeaders"
     "withGd"
     "enableCET"
     "postInstall"

pkgs/development/libraries/glibc/default.nix

···
   stdenv,
   callPackage,
   withLinuxHeaders ? true,
+  linuxHeaders ? null,
   profilingLibraries ? false,
   withGd ? false,
   enableCET ? if stdenv.hostPlatform.isx86_64 then "permissive" else false,
···
   ];
 in
 
-(callPackage ./common.nix { inherit stdenv; } {
+(callPackage ./common.nix { inherit stdenv linuxHeaders; } {
   inherit
     withLinuxHeaders
     withGd