Add a Force option to raw_fd_ostream to specify whether opening
an existing file is considered an error. Convert several tools
to use raw_fd_ostream instead of std::ostream, and to use this
new option instead of doing a manual check.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75801 91177308-0d34-0410-b5e6-96231b3b80d8
12 files changed