Rollup merge of #63419 - RalfJung:typeid, r=alexcrichton
Rollup merge of #63419 - RalfJung:typeid, r=alexcrichton

check against more collisions for TypeId of fn pointer

Cc https://github.com/rust-lang/rfcs/pull/2738#issuecomment-519923318

aidancully/rust,graydon/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust