Using removeComments from commandLineParser. This is more robust as it removes both single and multiline comments

src/compiler/commandLineParser.ts

@@ -503,7 +503,7 @@ namespace ts {
      *
      * This method replace comment content by whitespace rather than completely remove them to keep positions in json parsing error reporting accurate.
      */
-    function removeComments(jsonText: string): string {
+    export function removeComments(jsonText: string): string {
         let output = "";
         const scanner = createScanner(ScriptTarget.ES5, /* skipTrivia */ false, LanguageVariant.Standard, jsonText);
         let token: SyntaxKind;