Auto merge of rust-lang#105609 - bjorn3:shrink_rustc_dev, r=jyn514

Only include metadata for non-dynamic libraries in rustc-dev

The actual object code should be linked from librustc_driver.so, which is still included in rustc-dev. This saves on download time and disk usage.

Fixes rust-lang#103538

src/lib.rs

@@ -54,6 +54,11 @@ extern crate rustc_session;
 extern crate rustc_span;
 extern crate rustc_target;
 
+// Necessary to pull in object code as the rest of the rustc crates are shipped only as rmeta
+// files.
+#[allow(unused_extern_crates)]
+extern crate rustc_driver;
+
 mod borrow_tracker;
 mod clock;
 mod concurrency;