Auto merge of #141453 - compiler-errors:pgo-solver, r=Kobzol

[DONT MERGE] PGO new solver

🤔

I hope I did this right...

Author: bors

src/build_helper/src/lib.rs

@@ -29,4 +29,5 @@ pub const RUSTC_PGO_CRATES: &[&str] = &[
     "tuple-stress",
     "diesel-2.2.10",
     "bitmaps-3.2.1",
+    "serde-1.0.219-new-solver",
 ];