Drop BodyOfTransparent mode bit

 - premature optimization, we can just inspect the owner chain,
 - if we need it, it should be an automatically updated cache

Author: odersky

compiler/src/dotty/tools/dotc/core/Mode.scala

@@ -93,7 +93,4 @@ object Mode {
 
   /** We are in the IDE */
   val Interactive = newMode(20, "Interactive")
-
-  /** We are typing the body of a transparent method */
-  val TransparentBody = newMode(21, "TransparentBody")
 }

compiler/src/dotty/tools/dotc/typer/Namer.scala

@@ -1128,8 +1128,7 @@ class Namer { typer: Typer =>
       // it would be erased to BoxedUnit.
       def dealiasIfUnit(tp: Type) = if (tp.isRef(defn.UnitClass)) defn.UnitType else tp
 
-      var rhsCtx = ctx.addMode(Mode.InferringReturnType)
-      if (sym.isTransparentMethod) rhsCtx = rhsCtx.addMode(Mode.TransparentBody)
+      val rhsCtx = ctx.addMode(Mode.InferringReturnType)
       def rhsType = typedAheadExpr(mdef.rhs, inherited orElse rhsProto)(rhsCtx).tpe
 
       // Approximate a type `tp` with a type that does not contain skolem types.