Make LLVM command-line tools overwrite their output files without -f.

This is conventional command-line tool behavior. -f now just means
"enable binary output on terminals".

Add a -f option to llvm-extract and llvm-link, for consistency.

Remove F_Force from raw_fd_ostream and enable overwriting and
truncating by default. Introduce an F_Excl flag to permit users to
enable a failure when the file already exists. This flag is
currently unused.

Update Makefiles and documentation accordingly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79990 91177308-0d34-0410-b5e6-96231b3b80d8

utils/FileUpdate/FileUpdate.cpp

@@ -66,7 +66,7 @@ int main(int argc, char **argv) {
     outs() << argv[0] << ": Updating '" << OutputFilename
            << "', contents changed.\n";
   raw_fd_ostream OutStream(OutputFilename.c_str(), ErrorStr,
-                           raw_fd_ostream::F_Force|raw_fd_ostream::F_Binary);
+                           raw_fd_ostream::F_Binary);
   if (!ErrorStr.empty()) {
     errs() << argv[0] << ": Unable to write output '"
            << OutputFilename << "': " << ErrorStr << '\n';