Description:kernelspace musl code

Team:OTHERS
Feature or Bugfix:Feature
Binary Source:NA
PrivateCode(Yes/No):No

Change-Id: I99874a7c570b7d22b4a3d34840260eb48ea3ffa1
Reviewed-on: http://mgit-tm.rnd.huawei.com/10276995Reviewed-by: Nshenwei 00579521 <denny.shenwei@huawei.com>
Tested-by: Npublic jenkins <public_jenkins@notesmail.huawei.com>

per the resolution of Austin Group issue #617, these are accepted for
XSI option in POSIX future and thus I'm treating them as standard
functions.

per the standard, ffs is XSI shaded, whereas the other functions in
this header are in the base.

this should be everything except for some functions where the non-_l
version isn't even implemented yet (mainly some non-ISO-C wcs*
functions).

thanks to Peter Mazinger (psm) for pointing many of these issues out
and submitting a patch on which this commit is loosely based