stdenvAdapters: add overrideMkDerivationArgs

In addition to the use-case mentioned inside the function's
documentation comment, I am motivated to add this function for two
reasons:

- My actual use-case is adding a guaranteed phase to every
  `stdenv.mkDerivation` via a nixpkgs overlay. Exposing this generic
  function allows me to do that, without having to replicate
  `defaultMkDerivationFromStdenv`. This relieves that maintainence
  burden for that overlay implementation, since that function has to be
  kept in sync with `stdenv/generic`.

- I see value in adding this generic function over a specialized
  function. At first, I had a different implementation in mind, and
  tried to make due with the specialized functions that were already
  exposed. Having access to this generic function allowed me to
  experiment, and settle on a better implementation.

This commit is based off of @SomeoneSerge's PR [1].

[1] https://github.com/NixOS/nixpkgs/pull/350350

Co-authored-by: SomeoneSerge <else+aalto@someonex.net>

pkgs/stdenv/adapters.nix

@@ -215,6 +215,23 @@ rec {
       mkDerivationFromStdenv = extendMkDerivationArgs old (_: extraAttrs);
     });
 
+  /*
+    Modify a stdenv so as to extend `mkDerivation`'s arguments.
+    A stronger version of `addAttrsToDerivation`.
+
+    Example:
+      requireCcache =
+        overrideMkDerivationArgs
+           (oldAttrs: {
+             requiredSystemFeatures = oldAttrs.requiredSystemFeatures or [ ] ++ [ "ccache" ];
+           });
+  */
+  overrideMkDerivationArgs =
+    extension: stdenv:
+    stdenv.override (old: {
+      mkDerivationFromStdenv = extendMkDerivationArgs old extension;
+    });
+
   /*
     Use the trace output to report all processed derivations with their
     license name.