[clang] [Clang][Sema] Mark decomposition decl invalid for explicit array type (PR #210964)

[Shengxin Pei via cfe-commits]

https://github.com/TPPPP72 commented:

Please make sure you've got what @cor3ntin and I said. You should revert your previous change to assertion.

https://github.com/llvm/llvm-project/pull/210964