Fix wrong test in PatMat.

Call drop method directly if class derives from sequence.
I do not understand how callRuntime works in scalac. Calling this method requires implicit search.

Author: DarkDimius

src/dotty/tools/dotc/transform/PatternMatcher.scala

@@ -136,7 +136,7 @@ class PatternMatcher extends MiniPhaseTransform with DenotTransformer {thisTrans
         def callDirect   = tgt.select(nme.drop).appliedTo(Literal(Constant(n)))
         def callRuntime  = ref(defn.traversableDropMethod).appliedTo(tgt, Literal(Constant(n)))
 
-        def needsRuntime = tgt.tpe derivesFrom defn.SeqClass /*typeOfMemberNamedDrop(tgt.tpe) == NoType*/
+        def needsRuntime = !(tgt.tpe derivesFrom defn.SeqClass) /*typeOfMemberNamedDrop(tgt.tpe) == NoType*/
 
         if (needsRuntime) callRuntime else callDirect
       }