Multi output problem with delambdafied compilation

User code compilation with -Ybackend:GenBCode -Ydelambdafy:method
fails for projects with multiple output directories.
The problem has its root in a fact that some `lambdaClass` symbols
the `associatedFile` field is not set. It can be done in Delambdafy.scala
(`makeAnonymousClass` method) and is working for following lambda
examples:
{{{
package acme

object Delambdafy {
  type -->[D, I] = PartialFunction[D, I]

  def main(args: Array[String]): Unit = {
    val result = List(1, 2, 4).map { a =>
      val list = List("1", "2", "3").map { _ + "test" }
      list.find { _ == a.toString + "test" }
    }
    lazy val _foo = foo(result) {
      case x::xs if x isDefined => x.get.length
      case _ => 0
    }
    lazy val bar: Int => Int = {
      case 2 => 13
      case _ =>
        val v = List(1).map(_ + 42).head
	v + 1
    }
  }
  def foo(b: List[Option[String]])(a: List[Option[String]] => Int): Int =
  a(b)
}
}}}
but is NOT working for following lambda:
{{{
package acme

object Delambdafy {
  type -->[D, I] = PartialFunction[D, I]

  def main(args: Array[String]): Unit = {
    lazy val _baz = baz {
      case 1 =>
        val local = List(1).map(_ + 1)
	local.head
    }
  }
  def baz[T](f: Any --> Any): Any => Any = f
}
}}}
so that's why source of compilation unit is used to determine output
directory in case when source file is not found for symbol.

2 files changed, 23 insertions, 9 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
index 65a6b82570..813180a8c7 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
@@ -35,15 +35,26 @@ abstract class BCodeHelpers extends BCodeIdiomatic with BytecodeWriters {
   /*
    * must-single-thread
    */
-  def getOutFolder(csym: Symbol, cName: String, cunit: CompilationUnit): _root_.scala.tools.nsc.io.AbstractFile = {
-    try {
-      outputDirectory(csym)
-    } catch {
-      case ex: Throwable =>
-        reporter.error(cunit.body.pos, s"Couldn't create file for class $cName\n${ex.getMessage}")
-        null
-    }
-  }
+  def getOutFolder(csym: Symbol, cName: String, cunit: CompilationUnit): _root_.scala.tools.nsc.io.AbstractFile = Option {
+      try {
+        outputDirectory(csym)
+      } catch {
+        case ex: Throwable =>
+          reporter.warning(cunit.body.pos, s"Couldn't find output folder for symbol source ${csym.name}. Dropping to compliation unit source.\n${ex.getMessage}")
+          null
+      }
+    }.orElse { Option {
+      try {
+        outputDirectory(cunit.source)
+      } catch {
+        case ex: Throwable =>
+          reporter.warning(cunit.body.pos, s"Couldn't find output folder for compilation unit $cName\n${ex.getMessage}")
+	  null
+      }
+    }}.orElse {
+      reporter.error(cunit.body.pos, s"Couldn't create file for class $cName")
+      None
+    }.orNull
 
   var pickledBytes = 0 // statistics
 
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BytecodeWriters.scala b/src/compiler/scala/tools/nsc/backend/jvm/BytecodeWriters.scala
index 1d29fdee10..e4fcb729a2 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BytecodeWriters.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BytecodeWriters.scala
@@ -25,6 +25,9 @@ trait BytecodeWriters {
   def outputDirectory(sym: Symbol): AbstractFile =
     settings.outputDirs outputDirFor enteringFlatten(sym.sourceFile)
 
+  def outputDirectory(cunitSource: scala.reflect.internal.util.SourceFile): AbstractFile =
+    settings.outputDirs outputDirFor cunitSource.file
+
   /**
    * @param clsName cls.getName
    */