A quoted - is not the beginning of an option, and should not be completed as such.  This was causing:

(lldb) disassemble -n '-<TAB>

to crash.

<rdar://problem/18134531>


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@216626 91177308-0d34-0410-b5e6-96231b3b80d8