During source manager test, write back the file using binary mode.
During source manager test, write back the file using binary mode.

On Windows, opening with "w" opens it as text instead of binary.
This causes translation of newline characters, so that "\n" turns
into "\r\n", which in turn leads to git detecting that the file
has changed and wanting to commit it.

git-svn-id: 4c4cc70b1ef44ba2b7963015e681894188cea27e@226220 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb,llvm-mirror/lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb