[llvm] [AMDGPU][LowerModuleLDS] Handle non-dynlds zero sized type (PR #84742)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> Internal zero-sized-types in LDS seem tricky to handle. When they're external we can probably justify giving them all the same address, but when they're internal it's expected that they're different objects,

I don't think this is the case. I think all 0 sized allocations (within the same address space) should always get the same address regardless of the linkage 

https://github.com/llvm/llvm-project/pull/84742