linuxkpi: Add sort function

[manu]

Summary

Add sort function.
Obtain from drmkpi/drm2

[emaste]

Can we not use qsort from libkern?

sys/compat/linuxkpi/common/src/linux_sort.c

13

Can use 3. here. If this is modified from a userland copy we could update it to 3. also.

[manu]

In D27655#618025, @emaste wrote:

Can we not use qsort from libkern?

qsort have it's own swap function and cannot be defined, but I guess I can make a new one in libkern that can use a defined swap func.

sys/compat/linuxkpi/common/src/linux_sort.c

13

I need to see from where it really was copied from but yeah something is weird here.

[manu]

@wulf commited a different version in 7356f661e81d1ff88bdb4daa127f3bfa2be7ecb9