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

[Jonas Devlieghere via cfe-commits]

JDevlieghere wrote:

> But lldb sets itself apart in how hard it is to get a project setup going, and how impactful it is.

Can you elaborate on what specifically you find hard? Building should be fairly straightforward, besides Python and SWIG, which are required to run the test, most of our dependencies are optional. Unlike the compiler, the debugger is (1) tied to the system it's running on, and (2) an interactive tool, so maybe that's what you're referring to? Either way, if there are concrete ways we can make LLDB easier to work on, I'd love to hear your suggestions!

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