Auto merge of #111517 - lukas-code:addr-of-mutate, r=tmiasko

allow mutating function args through `&raw const`

Fixes rust-lang/rust#111502 by "turning off the sketchy optimization while we figure out if this is ok", like `@JakobDegen` said.

The first commit in this PR removes some suspicious looking logic from the same method, but should have no functional changes, since it doesn't modify the `context` outside of the method. Best reviewed commit by commit.

r? opsem