Merging r155293:

------------------------------------------------------------------------
r155293 | rsmith | 2012-04-21 11:42:51 -0700 (Sat, 21 Apr 2012) | 4 lines

Fix regression in r154844. If necessary, defer computing adjusted destructor
exception specifications in C++11 until after we've parsed the exception
specifications for nested classes.

------------------------------------------------------------------------

llvm-svn: 156683