This is the libclang patch providing minimal API to

use clang's formatter. Currently, formatter is used 
to format declaration tags for xml comments. Since formatter
is in flux and its change will break several of the clang comment
tests, only a single tests is formatted using this facility.
Doug has reviewed and approved it for check-in. 


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@170467 91177308-0d34-0410-b5e6-96231b3b80d8