make `try_find_coercion_lub` private; we always use `CoerceMany`
make `try_find_coercion_lub` private; we always use `CoerceMany`

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