[libclang] When there's a file error when saving the PCH, make sure to
clear the error from raw_fd_ostream, otherwise we will crash.

rdar://10976410

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@152605 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed