gobject-introspection: propagate self/targetself to avoid having to add gobject-introspection to buildInputs

i should probably move to use the wrapper when host != build and do the
canExecute things inside the wrapper.nix

then i could use gobject-introspection-unwrapped in it even when
host == build

void also adds gobject-introspection to makeDepends when its gir build
helper is used

pkgs/development/libraries/gobject-introspection/default.nix

@@ -138,6 +138,14 @@ stdenv.mkDerivation (finalAttrs: {
     rm $out/lib/libregress-1.0${stdenv.targetPlatform.extensions.sharedLibrary}
   '';
 
+  # add self to buildInputs to avoid needing to add gobject-introspection to buildInputs in addition to nativeBuildInputs
+  # builds use target-pkg-config to look for gobject-introspection instead of just looking for binaries in $PATH
+  # wrapper uses depsTargetTargetPropagated so ignore it
+  preFixup = lib.optionalString (!lib.hasSuffix "-wrapped" finalAttrs.pname) ''
+    mkdir -p $dev/nix-support
+    echo "$out" > $dev/nix-support/propagated-target-target-deps
+  '';
+
   setupHook = ./setup-hook.sh;
 
   passthru = {

pkgs/development/libraries/gobject-introspection/wrapper.nix

@@ -18,6 +18,7 @@ in
 
 (gobject-introspection-unwrapped.override args).overrideAttrs (previousAttrs: {
   pname = "gobject-introspection-wrapped";
+  depsTargetTargetPropagated = [ gobject-introspection-unwrapped ];
   postFixup = (previousAttrs.postFixup or "") + ''
     mv $dev/bin/g-ir-compiler $dev/bin/.g-ir-compiler-wrapped
     mv $dev/bin/g-ir-scanner $dev/bin/.g-ir-scanner-wrapped