[clang] [llvm] Add DW_ATE_GNU_complex_signed to fix assertion (PR #161695)

[David Blaikie via cfe-commits]

https://github.com/dwblaikie approved this pull request.

> It's just LLVM CodeGen that asserts

Oh, fascinating - so this has been a totally untested codepath? I guess release builds did just fine/didn't assert (because no assertions enabled) so it's probably been working fine for people for years in practice... 

https://github.com/llvm/llvm-project/pull/161695