Added a kqueue class which isn't being used yet, but was part of trying to work around the limitations with the unix select() call and how it is limited to FD_SETSIZE file descriptors.

Also added a TimeSpecTimeout class which can be used with any calls that take a "struct timespec *" as an argument. It is used by the KQueue class.

Also updated some project settings.



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@175377 91177308-0d34-0410-b5e6-96231b3b80d8
<rdar://problem/13121056>

Fixed a crasher when the ConnectionFileDescriptor was used in a process with over FD_SETSIZE (1024) files open. It would corrupt the stack and cause the stack checker to assert and kill the program.

The final fix was to "#define _DARWIN_UNLIMITED_SELECT" at the top of the one and only file that uses select () in the LLDB codebase and then make an array of "fd_set" objects so they can handle more than 1024 file descriptors. The new code can handle as many file descriptors as a process can create.    
    


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@175378 91177308-0d34-0410-b5e6-96231b3b80d8