Introduced a new src/etc/cat-and-grep.sh script (called in run-make as
$(CGREP)), which prints the input and do a grep simultaneously. This is
mainly used to debug spurious failures in run-make, such as the sanitizer
error in #45810, as well as real errors such as #46126.
The compiler will now issue a warning for crates that have syntax of the form
`extern crate "foo" as bar`, but it will still continue to accept this syntax.
Additionally, the string `foo-bar` will match the crate name `foo_bar` to assist
in the transition period as well.
This patch will land hopefully in tandem with a Cargo patch that will start
translating all crate names to have underscores instead of hyphens.
cc #23533
The filestem of the desired output isn't necessarily a valid crate id, and
calling unwrap() will trigger an ICE in rustc. This tries a little harder to
infer a "valid crate id" from a crate, with an eventual fallback to a generic
crate id if alll else fails.
Closes#11107
