Rollup merge of #107718 - Zoxc:z-time, r=nnethercote

Add `-Z time-passes-format` to allow specifying a JSON output for `-Z time-passes`

This adds back the `-Z time` option as that is useful for [my rustc benchmark tool](https://github.com/Zoxc/rcb), reverting rust-lang/rust#102725. It now uses nanoseconds and bytes as the units so it is renamed to `time-precise`.

Author: matthiaskrgr