Rollup merge of rust-lang#45203 - alexcrichton:update-llvm, r=michaelwoerister

rustc: Update LLVM with a ThinLTO fix

This commit updates LLVM with a patch that's landed upstream to fix an assertion
that was tripping when ThinLTO was activated. Unfortunately I wasn't able to get
a reduced test case, but I've tested manually on the affected crates and the
assertion is indeed fixed.

Closes rust-lang#45131

Author: kennytm