[clang] [clang][AST] Added assert to prevent infinite recursion in computing layout (PR #154134)

[via cfe-commits]

tgs-sc wrote:

> Because this can be hit by user-written expressions, I think an assert is actually the wrong fix; we should handle it gracefully. Otherwise, in asserts builds this is effectively a crash and in non-asserts builds it's still an infinite recursion.
> 
> CC @JDevlieghere @Michael137 for other opinions on the lldb side

The user expression only triggered parsing the part of dwarf that was incorrectly created.

> in asserts builds this is effectively a crash

Yes, that's exactly the reason why i want to add this assert here. Simply because it works better than infinite recursion.

This is an original PR, this patch was created from:
https://github.com/llvm/llvm-project/pull/154123

https://github.com/llvm/llvm-project/pull/154134