Make the preservation of formatting an optional experimental compiler flag.

src/compiler/commandLineParser.ts

@@ -140,6 +140,12 @@ module ts {
             description: Diagnostics.Do_not_emit_declarations_for_code_that_has_an_internal_annotation,
             experimental: true
         },
+        {
+            name: "preserveFormatting",
+            type: "boolean",
+            description: Diagnostics.Preserve_new_lines_when_emitting_code,
+            experimental: true
+        },
         {
             name: "target",
             shortName: "t",