jextract: install with bundle binaries

pkgs/development/tools/java/jextract/default.nix

@@ -77,17 +77,14 @@ stdenv.mkDerivation {
   installPhase = ''
     runHook preInstall
 
-    install -D --mode=0444 --target-directory="$out/share/java" \
-      ./build/libs/org.openjdk.jextract-unspecified.jar
+    mkdir -p $out/opt/
+    cp -r ./build/jextract $out/opt/jextract
 
     runHook postInstall
   '';
 
   postFixup = ''
-    makeWrapper "${jdk20}/bin/java" "$out/bin/jextract" \
-      --add-flags "--enable-preview" \
-      --add-flags "--class-path $out/share/java/org.openjdk.jextract-unspecified.jar" \
-      --add-flags "org.openjdk.jextract.JextractTool"
+    makeWrapper "$out/opt/jextract/bin/jextract" "$out/bin/jextract"
   '';
 
   meta = with lib; {