Remove -Ystop-after in exhaustivity tests

Author: liufengyun

compiler/test/dotty/tools/dotc/transform/PatmatExhaustivityTest.scala

@@ -16,8 +16,7 @@ import vulpix.TestConfiguration
 
 class PatmatExhaustivityTest {
   val testsDir = "tests/patmat"
-  // stop-after: patmatexhaust-huge.scala crash compiler
-  val options = List("-color:never", "-Ystop-after:crossCast", "-Ycheck-all-patmat", "-classpath", TestConfiguration.basicClasspath)
+  val options = List("-color:never", "-Ycheck-all-patmat", "-classpath", TestConfiguration.basicClasspath)
 
   private def compileFile(path: JPath) = {
     val stringBuffer = new StringWriter()