function langRe(value, global) {
      return new RegExp(
        source(value),
        'm'
        + (language.case_insensitive ? 'i' : '')
        + (language.unicodeRegex ? 'u' : '')
        + (global ? 'g' : '')
      );
    }
Builds a regex with the case sensitivity of the current language

@param {RegExp | string} value
@param {boolean} [global]