gnatcoll-core: fix build on x86_64-darwin

pkgs/development/tools/build-managers/gprbuild/gpr-project-path-hook.sh

@@ -6,3 +6,16 @@ addAdaObjectsPath() {
 }
 
 addEnvHooks "$targetOffset" addAdaObjectsPath
+
+fixDarwinRpath() {
+    for f in $(find $out -type f -executable); do
+        install_name_tool -id $f $f || true
+        for rpath in $(otool -L $f | grep rpath | awk '{print $1}'); do
+            install_name_tool -change $rpath $out/lib/$(basename $rpath) $f || true
+        done
+    done
+}
+
+if [ "$(uname)" = "Darwin" ]; then
+    preFixupPhases+=" fixDarwinRpath"
+fi