Add bsp JavaBuildServerForwardStubs

modules/bloop-rifle/src/main/scala/scala/build/bloop/BuildServer.scala

@@ -2,4 +2,4 @@ package scala.build.bloop
 
 import ch.epfl.scala.bsp4j
 
-trait BuildServer extends bsp4j.BuildServer with bsp4j.ScalaBuildServer
+trait BuildServer extends bsp4j.BuildServer with bsp4j.ScalaBuildServer with bsp4j.JavaBuildServer

modules/build/src/main/scala/scala/build/bsp/BspServer.scala

@@ -12,10 +12,10 @@ import scala.build.GeneratedSource
 import scala.build.Logger
 
 class BspServer(
-  bloopServer: b.BuildServer with b.ScalaBuildServer,
+  bloopServer: b.BuildServer with b.ScalaBuildServer with b.JavaBuildServer,
   compile: (() => CompletableFuture[b.CompileResult]) => CompletableFuture[b.CompileResult],
   logger: Logger
-) extends b.BuildServer with b.ScalaBuildServer with BuildServerForwardStubs with ScalaBuildServerForwardStubs with HasGeneratedSources {
+) extends b.BuildServer with b.ScalaBuildServer with BuildServerForwardStubs with ScalaBuildServerForwardStubs with JavaBuildServerForwardStubs with HasGeneratedSources {
 
   import BspServer._
 

modules/build/src/main/scala/scala/build/bsp/JavaBuildServerForwardStubs.scala

@@ -0,0 +1,13 @@
+package scala.build.bsp
+
+import ch.epfl.scala.bsp4j.{JavacOptionsParams, JavacOptionsResult}
+import ch.epfl.scala.{bsp4j => b}
+
+import java.util.concurrent.CompletableFuture
+
+trait JavaBuildServerForwardStubs extends b.JavaBuildServer {
+  protected def forwardTo: b.JavaBuildServer
+
+  override def buildTargetJavacOptions(params: JavacOptionsParams): CompletableFuture[JavacOptionsResult] =
+    forwardTo.buildTargetJavacOptions(params)
+}