Unrolled build for rust-lang#126073

Rollup merge of rust-lang#126073 - Zalathar:fulldeps-borrowck, r=jieyouxu

Port `tests/run-make-fulldeps/obtain-borrowck` to ui-fulldeps

Thanks to `{{sysroot-base}}` from rust-lang#126008, this was also pretty straightforward to port over.

Author: rust-timer

tests/run-make-fulldeps/obtain-borrowck/Makefile

@@ -1,3 +1,5 @@
+#![allow(dead_code)]
+
 trait X {
     fn provided(&self) -> usize {
         5

tests/run-make-fulldeps/obtain-borrowck/test.rs renamed to tests/ui-fulldeps/auxiliary/obtain-borrowck-input.rs

@@ -1,3 +1,10 @@
+//@ edition: 2021
+//@ run-pass
+//@ check-run-results
+//@ run-flags: --sysroot {{sysroot-base}} --edition=2021 {{src-base}}/auxiliary/obtain-borrowck-input.rs
+//@ ignore-stage1 (requires matching sysroot built with in-tree compiler)
+// ignore-tidy-linelength
+
 #![feature(rustc_private)]
 
 //! This program implements a rustc driver that retrieves MIR bodies with