Merge pull request #2572 from Microsoft/seriouslyWhyWouldntYouWantComments

Keep comments in debug builds.

Author: DanielRosenwasser

Jakefile

@@ -222,15 +222,17 @@ function compileFile(outFile, sources, prereqs, prefixes, useBuiltCompiler, noOu
         var dir = useBuiltCompiler ? builtLocalDirectory : LKGDirectory;
         var options = "--module commonjs -noImplicitAny";
 
-        if (!keepComments) {
-            options += " -removeComments";
+        // Keep comments when specifically requested
+        // or when in debug mode.
+        if (!(keepComments || useDebugMode)) {
+            options += " --removeComments";
         }
 
         if (generateDeclarations) {
             options += " --declaration";
         }
 
-        if (useDebugMode || preserveConstEnums) {
+        if (preserveConstEnums || useDebugMode) {
             options += " --preserveConstEnums";
         }