Append newline to EOF for .txt test data files

Reverts and fixes 102f0d3

compiler/testData/diagnostics/tests/dataFlowInfoTraversal/smartcasts/SmartcastAmbiguitites.txt

@@ -15,4 +15,4 @@ internal final class C {
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
-}
+}

compiler/testData/diagnostics/tests/dataFlowInfoTraversal/smartcasts/SmartcastsForStableIdentifiers.txt

@@ -53,4 +53,4 @@ package example {
     package example.ns {
         internal val y: kotlin.Any? = 2
     }
-}
+}