Pressing ^D in a non-empty input terminates LLDB. This was due to the fact that we stack more than one editline instance on top of each other and we still expect CTRL+D to exit the editline instance, but it should only do so when the line is empty. Otherwise it should (and does) delete the character at the cursor.

<rdar://problem/15944703>


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@200489 91177308-0d34-0410-b5e6-96231b3b80d8