output code hint at skipping preparse of immediately invoked things

[stefanpenner]

given:
var ComponentDefinition$1 = function (_GlimmerComponentDefi) {

Adding a wrapping ( and trailing ) before the () would hint to v8 and friends that this shouldn't be pre-parsed, just parsed. This should help minimize initial parse/eval cost.

var ComponentDefinition$1 = (function (_GlimmerComponentDefi) {

Be sure the uglification step doesn't strip these, or it may defeat this..