Eliminate unnecessary functions for literals.

[tbranyen]

defines that use literals should not be converted to IIFE that return the value, we should just directly assign.

Example:

define(1234);

which currently compiles to:

var __AMDCLEAN0__ = (function() {
  return 1234;
})();

but, should be optimized to:

var __AMDCLEAN0__ = 1234;

[jugglinmike]

define(function() {
  return function() {
    /* my function */
  });
});

Could also be optimized:

var __AMDCLEAN0__ = function() {
  /* my function */
};

[jugglinmike]

Forget it!