Remove backend "compatibility layer"

Author: OlivierBlanvillain

compiler/src/dotty/tools/backend/jvm/DottyBackendInterface.scala

@@ -11,7 +11,7 @@ import java.io.{File => _}
 import scala.collection.generic.Clearable
 import scala.collection.mutable
 import scala.reflect.ClassTag
-import scala.reflect.internal.util.WeakHashSet
+import dotty.tools.dotc.util.WeakHashSet
 import dotty.tools.io.AbstractFile
 import scala.tools.asm.AnnotationVisitor
 import scala.tools.nsc.backend.jvm.{BCodeHelpers, BackendInterface}

compiler/src/dotty/tools/backend/jvm/GenBCode.scala

@@ -105,7 +105,7 @@ class GenBCodePipeline(val entryPoints: List[Symbol], val int: DottyBackendInter
     /* ---------------- q2 ---------------- */
 
     case class SubItem2(classNode: asm.tree.ClassNode,
-                        file:      scala.tools.nsc.io.AbstractFile)
+                        file:      dotty.tools.io.AbstractFile)
 
     case class Item2(arrivalPos: Int,
                      mirror:     SubItem2,
@@ -128,7 +128,7 @@ class GenBCodePipeline(val entryPoints: List[Symbol], val int: DottyBackendInter
     case class SubItem3(
                          jclassName:  String,
                          jclassBytes: Array[Byte],
-                         jclassFile:  scala.tools.nsc.io.AbstractFile
+                         jclassFile:  dotty.tools.io.AbstractFile
                          )
 
     case class Item3(arrivalPos: Int,

compiler/src/scala/reflect/internal/pickling/package.scala

@@ -9,7 +9,7 @@ package backend.jvm
 
 import scala.tools.asm
 import scala.collection.mutable
-import scala.tools.nsc.io.AbstractFile
+import dotty.tools.io.AbstractFile
 
 /*
  *  Traits encapsulating functionality to convert Scala AST Trees into ASM ClassNodes.
@@ -41,7 +41,7 @@ trait BCodeHelpers extends BCodeIdiomatic with BytecodeWriters {
   /*
    * must-single-thread
    */
-  def getOutFolder(csym: Symbol, cName: String): _root_.scala.tools.nsc.io.AbstractFile = {
+  def getOutFolder(csym: Symbol, cName: String): AbstractFile = {
     try {
       csym.outputDirectory
     } catch {
@@ -145,7 +145,7 @@ trait BCodeHelpers extends BCodeIdiomatic with BytecodeWriters {
    */
   trait BCPickles {
 
-    import scala.reflect.internal.pickling.{ PickleFormat, PickleBuffer }
+    import dotty.tools.dotc.core.unpickleScala2.{ PickleFormat, PickleBuffer }
 
     val versionPickle = {
       val vp = new PickleBuffer(new Array[Byte](16), -1, 0)

compiler/src/scala/reflect/internal/util/package.scala

@@ -2,7 +2,7 @@ package scala.tools.nsc.backend.jvm
 
 import scala.collection.generic.Clearable
 import scala.reflect.ClassTag
-import scala.tools.nsc.io.AbstractFile
+import dotty.tools.io.AbstractFile
 import scala.language.implicitConversions
 import scala.tools.asm
 
@@ -657,7 +657,7 @@ abstract class BackendInterface extends BackendInterfaceDefinitions {
     def newWeakMap[K, V](): collection.mutable.WeakHashMap[K, V]
     def newMap[K, V](): collection.mutable.HashMap[K, V]
     def newSet[K](): collection.mutable.Set[K]
-    def newWeakSet[K >: Null <: AnyRef](): reflect.internal.util.WeakHashSet[K]
+    def newWeakSet[K >: Null <: AnyRef](): dotty.tools.dotc.util.WeakHashSet[K]
     def newAnyRefMap[K <: AnyRef, V](): collection.mutable.AnyRefMap[K, V]
   }
 

compiler/src/scala/tools/nsc/backend/jvm/BCodeHelpers.scala

@@ -7,7 +7,7 @@ package scala.tools.nsc
 package backend.jvm
 
 import java.io.{ DataOutputStream, FileOutputStream, IOException, OutputStream, File => JFile }
-import scala.tools.nsc.io._
+import dotty.tools.io._
 import java.util.jar.Attributes.Name
 import scala.language.postfixOps
 
@@ -85,7 +85,7 @@ trait BytecodeWriters {
 
     private val baseDir = Directory(int.emitAsmp.get).createDirectory()
 
-    private def emitAsmp(jclassBytes: Array[Byte], asmpFile: io.File): Unit = {
+    private def emitAsmp(jclassBytes: Array[Byte], asmpFile: dotty.tools.io.File): Unit = {
       val pw = asmpFile.printWriter()
       try {
         val cnode = new asm.tree.ClassNode()