Rustc reports error on Ctrl-C during linking

[bjorn3]

^C
gh-bjorn3@dev-desktop-eu-1:~/cg_clif$ error: linking with `cc` failed: signal: 2 (SIGINT)
  |
  = note: LC_ALL="C" PATH="/home/gh-bjorn3/cg_clif/dist/lib/rustlib/aarch64-unknown-linux-gnu/bin:/home/gh-bjorn3/.local/bin:/home/gh-bjorn3/.cargo/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin" VSLANG="1033" "cc" "/tmp/rustc3QDuN1/symbols.o" [...]
  = note: 

error: aborting due to 1 previous error

Rustc should probably check if it received SIGINT itself and if so ignore child processes exiting with SIGINT.

This is almost certainly a regression from #111769