function _getMungedName(identName, state) {
  var mungeNamespace = state.mungeNamespace;
  var shouldMinify = state.g.opts.minify;

  if (shouldMinify) {
    if (!_mungedSymbolMaps[mungeNamespace]) {
      _mungedSymbolMaps[mungeNamespace] = {
        symbolMap: {},
        identUUIDCounter: 0
      };
    }

    var symbolMap = _mungedSymbolMaps[mungeNamespace].symbolMap;
    if (!symbolMap[identName]) {
      symbolMap[identName] =
        base62.encode(_mungedSymbolMaps[mungeNamespace].identUUIDCounter++);
    }
    identName = symbolMap[identName];
  }
  return '$' + mungeNamespace + identName;
}
Given an identifier name, munge it using the current state's mungeNamespace.

@param {string} identName
@param {object} state
@return {string}