it changes raw_fd_ostream::preferred_buffer_size to return zero on
a scary stat failure instead of setting the stream to an error state.
This method really should not mutate the stream.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91740 91177308-0d34-0410-b5e6-96231b3b80d8
means that raw_ostream no longer has to #include <iosfwd>. Nothing in llvm
should use raw_os_ostream.h, but llvm-gcc and some unit tests do.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79886 91177308-0d34-0410-b5e6-96231b3b80d8