core: Inline `From<AllocErr> for CollectionAllocErr`
core: Inline `From<AllocErr> for CollectionAllocErr`

This shows up in allocations of vectors and such, so no need for it to not be
inlined!

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