Auto merge of rust-lang#103812 - clubby789:improve-include-bytes, r=petrochenkov

Delay `include_bytes` to AST lowering

Hopefully addresses rust-lang#65818.
This PR introduces a new `ExprKind::IncludedBytes` which stores the path and bytes of a file included with `include_bytes!()`. We can then create a literal from the bytes during AST lowering, which means we don't need to escape the bytes into valid UTF8 which is the cause of most of the overhead of embedding large binary blobs.

Author: bors