[llvm] [cross-project-tests] Add `has-gdb` LIT feature (PR #188780)

[via llvm-commits]

dyung wrote:

> > > > @Michael137 this change is causing the test sret.cpp in the cross-project-tests suite to fail on a bot. Can you take a look?
> > 
> > 
> > > > https://lab.llvm.org/buildbot/#/builders/163/builds/37218
> > 
> > 
> > > 
> > 
> > 
> > > Should be fixed
> > 
> > 
> > Which commit fixed this? It appears to still be failing on the bot.
> > https://lab.llvm.org/buildbot/#/builders/163/builds/37267
> 
> Hmm i remember fixing it on one of the builders yesterday. Let me check

Was it f7feb2ad47fe0976a9148d8ca35f8a8f9dcb5fa9? That fixed it on the darwin builder, but this is a linux based builder.

https://github.com/llvm/llvm-project/pull/188780