Harden type checking for enum values

This is a follow-up of #11327. We cannot generalize further without
complications:

```
val b = 'b'

56 match
case 'a' =>
case `b` =>
```

Author: liufengyun

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

@@ -3803,7 +3803,7 @@ class Typer extends Namer
               mapOver(tp)
         }
 
-        if tree.symbol.is(Module)
+        if tree.symbol.isOneOf(Module | Enum)
            && !(tree.tpe frozen_<:< pt) // fast track
            && !(tree.tpe frozen_<:< approx(pt))
         then

tests/neg/i9740b.scala

@@ -0,0 +1,19 @@
+enum Recovery:
+  case RecoveryCompleted
+
+enum TypedRecovery:
+  case TypedRecoveryCompleted
+
+import Recovery.*
+import TypedRecovery.*
+
+class Test {
+  TypedRecoveryCompleted match {
+    case RecoveryCompleted => println("Recovery completed")            // error
+    case TypedRecoveryCompleted => println("Typed recovery completed")
+  }
+
+  def foo(x: TypedRecovery) = x match
+    case RecoveryCompleted =>             // error
+    case TypedRecoveryCompleted =>
+}