Provide API migration guide for exception handling in LLVM 3.0

[DougGregor]

Bugzilla Link	11057
Resolution	LATER
Resolved on	Oct 27, 2013 00:13
Version	trunk
OS	All
CC	@isanbard

Extended Description

Exception handling was overhauled for LLVM 3.0. We should have a guide available as part of LLVM 3.0 that describes how to migrate from the old EH APIs to the new EH APIs.

[llvmbot]

This talk doesn't explain how to convert, but it does describe the basics of the
new eh setup:
http://llvm.org/devmtg/2011-09-16/EuroLLVM2011-ExceptionHandling.pdf

[lattner]

This should just go into the release notes like all other api changes.