[clang] [llvm] Enable LLDB tests in pre-merge CI (PR #94208)

[Vlad Serebrennikov via cfe-commits]

Endilll wrote:

> Should we just run the tests for the LLDB C++ language plugin (i.e., the part of LLDB that invokes Clang and the JIT). And then we could expand the set of tests from there later?

In the bash script that currently handles this, "targets that we need to check if lldb is tested" is expressible, but "targets that we need to check if lldb is tested on clang changes" is not, and I consider it already too complicated for a bash script.

https://github.com/llvm/llvm-project/pull/94208