Disable optimization

The inline labels optimization is no longer needed. It was also
incorrect. To verify: Compile classpath/AggregateClassPath with optimization to witness
a crash in the backend:

    Key not found: case3

The optimization incorrectly eliminates the label even though it is called
twice by the generated code. maybe it does not detect case labels called with parameters?

Author: odersky

compiler/src/dotty/tools/dotc/transform/localopt/Simplify.scala

@@ -41,7 +41,7 @@ class Simplify extends MiniPhaseTransform with IdentityDenotTransformer {
     new InlineCaseIntrinsics(this)  ::
     new RemoveUnnecessaryNullChecks ::
     new InlineOptions               ::
-    new InlineLabelsCalledOnce      ::
+    //new InlineLabelsCalledOnce    :: // not needed: new pattern matcher does this already
     new Valify(this)                ::
     new Devalify                    ::
     new Jumpjump                    ::