Rollup merge of #89615 - willcrichton:fix-get-body-with-borrowck-facts, r=oli-obk

Rollup merge of #89615 - willcrichton:fix-get-body-with-borrowck-facts, r=oli-obk

Add InferCtxt::with_opaque_type_inference to get_body_with_borrowck_facts

`mir_borrowck` uses `with_opaque_type_inference` before calling `do_mir_borrowck`: https://github.com/rust-lang/rust/blob/0eabf25b90396dead0b2a1aaa275af18a1ae6008/compiler/rustc_borrowck/src/lib.rs#L132

However `get_body_with_borrowck_facts` does not. Therefore I get an ICE eg when calling this function on the bodies of an async function as described here: https://rust-lang.zulipchat.com/#narrow/stream/182449-t-compiler.2Fhelp/topic/.E2.9C.94.20ICE.20when.20using.20get_body_with_borrowck_facts.20with.20async

This change fixes that bug.

r? `@nikomatsakis`