[clang] [clang][Sema] Fix false positive -Wshadow with structured binding captures (PR #157667)

[Yanzuo Liu via cfe-commits]

zwuis wrote:

IIUC we shouldn't emit any warning on "lambda captures shadow something". It is a better approach for me that removing emitting this warning and performing code cleanup (there must be some checks preventing false positive with shadowing variables).

https://github.com/llvm/llvm-project/pull/157667