Rollup merge of #49915 - llogiq:doc-shift-types, r=joshtriplett
Rollup merge of #49915 - llogiq:doc-shift-types, r=joshtriplett

[doc] note the special type inference handling for shift ops

This adds a note to the docs about the difference between the shift ops and the corresponding trait methods when it comes to type inference.

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