Rolling back r9709, which replaced remaining uses of the legacy 'compiler.emulatedStack' property
with the corresponding 'compiler.stackMode'.

Fixes issues: 5692

Review at http://gwt-code-reviews.appspot.com/1338804

Review by: atrenk@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@9715 8db76d5a-ed1c-0410-87a9-c151d255dfc7