[clang] [analyzer] Ignoring `T v=v; ` idiom for uninitialized variable checker and dead store checker (PR #187530)

[Ella Ma via cfe-commits]

Snape3058 wrote:

I added the fix for the dead store checker just now, as the test case can be reused for it.
I don't know whether I need to invite other colleagues to further review this part. If so, please help add them. Thx

https://github.com/llvm/llvm-project/pull/187530