Build musl dist artifacts with debuginfo enabled
Since our musl targets link to a version of musl we build and bundle
with the targets, if users need to debug into musl or generate
backtraces which contain parts of the musl library, they will be unable
to do so unless we enable and ship the debug info.
This patch changes our dist builds so they enabled debug info when
building musl. This patch also includes a fix for CFI detection in
musl's `configure` script which has been [posted upstream](https://www.openwall.com/lists/musl/2021/10/21/2).
The net effect of this is that we now ship debug info for musl in those
targets. This adds ~90kb to those artifacts but running `strip` on
binaries produced removes all of that. For a "hello world" Rust binary
on x86_64, the numbers are:
| | debug | release | release + strip |
| - | - | - | - |
| without musl debuginfo | 507kb | 495kb | 410kb |
| with musl debuginfo | 595kb | 584kb | 410kb |
Once stripped, the final binaries are the same size (down to the byte).
Fixes#90103
r? `@Mark-Simulacrum`
3b0249b1c9