[llvm] DWARF: Emit `DW_AT_artificial` on artificial globals (PR #93118)

[David Blaikie via llvm-commits]

dwblaikie wrote:

Applying a property of the type to the variable seems questionable to me. In the local variable case the flag is carried on the variable, by the looks of it, which is sound/not the same as what's being proposed here.

Perhaps other folks can chime in as to whether it's worth putting a Flags attribute on DIGlobalVariable - perhaps merging in the couple of booleans that are there already (IsLocalToUnit and IsDefinition) & maybe flags goes up to DIVariable to share between DILocal and DIGlobal variables.

https://github.com/llvm/llvm-project/pull/93118