[clang] [lldb] clang: Do not overwrite a module's DataLayout in the backend (PR #224012)

[Matt Arsenault via cfe-commits]

arsenm wrote:

> I' not sure, but the buildbot [lldb-remote-linux-win](https://lab.llvm.org/buildbot/#/builders/197/builds/19115) is broken probably after this patch. Please take a look.
> 
> ```
> FAIL: lldb-shell::unknown-udt-decl.ll
> FAIL: lldb-shell::rust-unique-name.ll


This is because the host datalayout mismatches the test's datalayout. The test content needs to require the host to match the file's triple/datalayout, or the file datalayout needs to be removed 

https://github.com/llvm/llvm-project/pull/224012