[clang-tools-extra] [clang-tidy] Add new check 'misc-scope-reduction' (PR #175429)

[Baranov Victor via cfe-commits]

vbvictor wrote:

FYI there is https://github.com/llvm/llvm-project/pull/171086 that is partially about scope reduction.

https://github.com/llvm/llvm-project/pull/175429