Remove -Ywarn-value-discard alias

Author: cb372

compiler/src/dotty/tools/dotc/config/ScalaSettings.scala

@@ -157,7 +157,7 @@ private sealed trait WarningSettings:
   self: SettingGroup =>
   val Whelp: Setting[Boolean] = BooleanSetting("-W", "Print a synopsis of warning options.")
   val XfatalWarnings: Setting[Boolean] = BooleanSetting("-Werror", "Fail the compilation if there are any warnings.", aliases = List("-Xfatal-warnings"))
-  val YwarnValueDiscard: Setting[Boolean] = BooleanSetting("-Wvalue-discard", "Warn when non-Unit expression results are unused.", aliases = List("-Ywarn-value-discard"))
+  val WvalueDiscard: Setting[Boolean] = BooleanSetting("-Wvalue-discard", "Warn when non-Unit expression results are unused.")
 
   val Wunused: Setting[List[String]] = MultiChoiceSetting(
     name = "-Wunused",

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

@@ -3928,7 +3928,7 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
         // so will take the code path that decides on inlining
         val tree1 = adapt(tree, WildcardType, locked)
         checkStatementPurity(tree1)(tree, ctx.owner)
-        if (!ctx.isAfterTyper && !tree.isInstanceOf[Inlined] && ctx.settings.YwarnValueDiscard.value) {
+        if (!ctx.isAfterTyper && !tree.isInstanceOf[Inlined] && ctx.settings.WvalueDiscard.value) {
           report.warning(ValueDiscarding(tree.tpe), tree.srcPos)
         }
         return tpd.Block(tree1 :: Nil, Literal(Constant(())))