[llvm] [lit] Update internal shell lexer to handle LLDB persistent vars. (PR #156125)

[via llvm-commits]

cmtice wrote:

> This needs a test in `llvm/utils/lit/tests`.
> 
> Adding some information in the PR description on what LLDB tests are impacted by this would also be helpful. There are some existing issues related to enabling the lit internal shell in LLDB, and adding a link to those (particularly #102698, none of the others look relevant) wouldn't hurt.

I updated an existing internal shell lexer test to test for this.  I also updated the PR description, giving a lot more detail.  Also mentioned this PR in issue #102698.



https://github.com/llvm/llvm-project/pull/156125