Fix for JsPointerToString and JsCreateString #6669

[dagarxji]

#6669

• Update for JsPointerToString and JsCreateString to ignore input string if length is 0. The function will return an empty string instead of JsErrorNullArgument.
• This passed all unit tests.
• The test included in the JsRTApiTest will fail without these changes.

Tagged as per issue request: @rhuanjl

[dagarxji]

Well noted. I have updated the files as requested. Hopefully that will remove all of the issues.

[rhuanjl]

Looks good apart from the test failure. I think it may be because you've put the PERFORM_JSRT_TTD_RECORD_ACTION macro inside the 'if' in one of the functions - can you move that so it's always called then hopefully the test will pass.