[clang] [llvm] [clang][CUDA] Allow `extern __shared__` on non-array types (PR #183879)

[Yaxun Liu via cfe-commits]

yxsamliu wrote:

Could you also update the PR description? It still calls the complete struct a dynamic shared-memory overlay. In non-RDC mode it uses fixed shared storage, as the new documentation explains. Saying this allows the declaration for NVCC compatibility would be clearer.

https://github.com/llvm/llvm-project/pull/183879