Rollup merge of #127934 - Kobzol:checktools-better-error, r=onur-ozkan

Improve error when a compiler/library build fails in `checktools.sh`

Suggested by ``@RalfJung`` [here](rust-lang/rust#127869 (comment)).

`x86_64-gnu-tools` should take ~45 minutes, let's see if this doesn't regress it.

r? ``@onur-ozkan``

Author: matthiaskrgr