LLVM: fix memory leak of debug type names

This required adjusting `Type.nameAlloc` to be used with a
general-purpose allocator and added `Type.nameAllocArena` for the arena
use case (avoids allocation sometimes).
fb4ad37e0bAndrew Kelley committed on 3/8/2022, 10:03:03 PMparent874b51d
4 files changedLine totals unavailable