destructuring_assignment fails to optimize code as well as mem::swap

[veber-alex]

Opening a new bug as requested in #90521 (comment)

I wanted to check how (a,b) = (b,a) compares to mem::swap, it looks like mem::swap applies optimizations when T is 32 bytes or bigger but destructuring_assignment doesn't.

I tried this code:
https://godbolt.org/z/czfTv3nzW

I expected to see this happen:
Both function should generate the same (optimal) code

Instead, this happened:
mem::swap applies optimizations while destructuring_assignment doesn't