Fixed Mac M1 support

[yoshimoto]

Fixed a issue #348 by importing the latest config.sub from
https://git.savannah.gnu.org/cgit/config.git/plain/config.sub.

[colinbrislawn]

Looks like this built ok...

Is this ready to merge?

[cheungxi]

This pr not updated config.guess. It will fail when build for loongarch64 CPU. @yoshimoto
How to pr your pr, haha.

[yoshimoto]

@cheungxi Thank you. I've updated both of config.guess and config.sub.

However, the check on ubuntu-18.04 (oldrel-4) seems to have failed. Is this an another issue or not?

[cheungxi]

why no people review this pr ?

[colinbrislawn]

Looks like there's one error in one build:

* creating vignettes ... ERROR
Error: Error: processing vignette 'function-comparisons.Rmd' failed with diagnostics:
could not find function "pandoc_math_engines"
Execution halted

I'm not sure what would cause that error...

[yoshimoto]

I re-ran the check and all tests have passed now.

For your information, I ran the check three times via same code, and got three different results:
1st: failed with https://github.com/r-lib/fs/runs/5473509786?check_suite_focus=true
2nd: failed with https://github.com/r-lib/fs/runs/5731473279?check_suite_focus=true
3rd: no error
I believe both 2 errors were false alarms and should be ignored here.

[cheungxi]

Can merge to master ? @gaborcsardi