Reword resolve errors caused by likely missing crate in dep tree

[estebank]

Reword label and add help:

error[E0432]: unresolved import `some_novel_crate`
 --> f704.rs:1:5
  |
1 | use some_novel_crate::Type;
  |     ^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `some_novel_crate`
  |
  = help: if you wanted to use a crate named `some_novel_crate`, use `cargo add some_novel_crate` to add it to your `Cargo.toml`

Fix #133137.

[rustbot]

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[fmease]

Please only suggest Cargo-specific stuff if rustc_session::utils::was_invoked_from_cargo()

[jieyouxu]

Please only suggest Cargo-specific stuff if rustc_session::utils::was_invoked_from_cargo()

Apparently that detection checks for CARGO_CRATE_NAME and tests have been using

//@ revisions: only-rustc cargo-invoked
//@[only-rustc] unset-rustc-env:CARGO_CRATE_NAME
//@[cargo-invoked] rustc-env:CARGO_CRATE_NAME=foo

which is... clever, almost too clever.

[rustbot]

The Miri subtree was changed

cc @rust-lang/miri