Re-implement runAsync to improve code size.

The new formulation doesn't try to tickle optimizers so much, and as a result can share a lot more code than the old implementation.

http://gwt-code-reviews.appspot.com/1442807/


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@10216 8db76d5a-ed1c-0410-87a9-c151d255dfc7
29 files changed