stripLazyRef for underlyingMatchType

Part of the changes needed to make
`tryNormalize.exists ==> underlyingMatchType.exists`

Also allows removing `override def tryNormalize` from `LazyRef`

Author: EugeneFlesselle

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

@@ -468,7 +468,7 @@ object Types extends TypeUtils {
     /** Does this application expand to a match type? */
     def isMatchAlias(using Context): Boolean = underlyingMatchType.exists
 
-    def underlyingMatchType(using Context): Type = this.safeDealias match
+    def underlyingMatchType(using Context): Type = this.safeDealias.stripLazyRef match
       case tp: MatchType => tp
       case tp: AppliedType => tp.underlyingMatchType
       case _ => NoType
@@ -3226,8 +3226,6 @@ object Types extends TypeUtils {
     private var myRef: Type | Null = null
     private var computed = false
 
-    override def tryNormalize(using Context): Type = ref.tryNormalize
-
     def ref(using Context): Type =
       if computed then
         if myRef == null then