Rollup merge of #42466 - wesleywiser:fix_42407, r=arielb1
Rollup merge of #42466 - wesleywiser:fix_42407, r=arielb1

syntax_pos::Symbol should not implement Sync

Fixes #42407

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