Refactors to provide two variants for evaluation of text_list:

- The original test now passes on Linux with clang because a breakpoint is hit prior to evaluation of text_list, which improves text coverage.
- The new test fails because 4 steps are requested, and only two occur prior to evaluation of text_list.
--- Note that the loss of every second "next" command can be reproduced using lldb manually with this script.

llvm-svn: 182860