Rollup merge of #54209 - petrochenkov:mexpr, r=pnkfelix
Rollup merge of #54209 - petrochenkov:mexpr, r=pnkfelix

Partially revert 674a5db "Fix undesirable fallout [from macro modularization]"

Partially revert https://github.com/rust-lang/rust/commit/674a5db1a50e25dd60a8ee6669edee9a366c9fab

~~Closes~~ (see pnkfelix comments below) https://github.com/rust-lang/rust/issues/53675

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