Add unitExpr and nullExpr to defn

Author: nicolasstucki

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

@@ -630,6 +630,8 @@ class Definitions {
 
   @tu lazy val QuotedExprClass: ClassSymbol = ctx.requiredClass("scala.quoted.Expr")
   @tu lazy val QuotedExprModule: Symbol = QuotedExprClass.companionModule
+    @tu lazy val QuotedExprModule_nullExpr: Symbol = QuotedExprModule.requiredMethod(nme.nullExpr)
+    @tu lazy val QuotedExprModule_unitExpr: Symbol = QuotedExprModule.requiredMethod(nme.unitExpr)
 
   @tu lazy val QuoteContextClass: ClassSymbol = ctx.requiredClass("scala.quoted.QuoteContext")
   @tu lazy val QuoteContextModule: Symbol = QuoteContextClass.companionModule

compiler/src/dotty/tools/dotc/transform/ReifyQuotes.scala

@@ -208,8 +208,8 @@ class ReifyQuotes extends MacroTransform {
 
       def pickleAsLiteral(lit: Literal) =
         lit.const.tag match {
-          case Constants.NullTag => ref(defn.QuotedExprModule).select(nme.nullExpr)
-          case Constants.UnitTag => ref(defn.QuotedExprModule).select(nme.unitExpr)
+          case Constants.NullTag => ref(defn.QuotedExprModule_nullExpr)
+          case Constants.UnitTag => ref(defn.QuotedExprModule_unitExpr)
           case _ => // Lifted literal
             val ltp = defn.LiftableClass.typeRef.appliedTo(ConstantType(lit.const))
             val liftable = ctx.typer.inferImplicitArg(ltp, body.span)