Address the clang 13 "changed binding to STB_WEAK" warning on arm (32bit):
* add _?ENTRY_NB to arm/asm.h
* make sure ld.so's arm asm bits see the same includes as libc
* switch libc's arm bits to the generic DEFS.h
* switch arm ASM bits from ENTRY to ENTRY_NB as necessary

ok kettenis@ miod@

Stop exporting _memcpy, an implementation detail of bcopy/memcpy/memmove

ok kettenis@ deraadt@

Use internal names for __errno, _memcpy, memset, and {,_}{set,long}jmp
Eliminate pointless use of PIC_SYM()
Split out DEFS.h from SYS.h like some other archs

ok kettenis@ deraadt@

Add framework for resolving (pun intended) libc namespace issues, using
wrapper .h files and asm labels to let internal calls resolve directly and
not be overridable or use the PLT. Then, apply that framework to most of
the functions in stdio.h, string.h, err.h, and wchar.h. Delete the
should-have-been-hidden-all-along _v?(err|warn)[cx]? symbols while here.

tests clean on i386, amd64, sparc64, powerpc, and mips64

naming feedback from kettenis@ and millert@
ok kettenis@

First pass at removing clauses 3 and 4 from NetBSD licenses.

Not sure what's more surprising: how long it took for NetBSD to
catch up to the rest of the BSDs (including UCB), or the amount of
code that NetBSD has claimed for itself without attributing to the
actual authors.

OK deraadt@

ARGH, forgot tags.

arm libc support. From NetBSD. currently supports softfloat.

Stop exporting _memcpy, an implementation detail of bcopy/memcpy/memmove

ok kettenis@ deraadt@

Use internal names for __errno, _memcpy, memset, and {,_}{set,long}jmp
Eliminate pointless use of PIC_SYM()
Split out DEFS.h from SYS.h like some other archs

ok kettenis@ deraadt@

Add framework for resolving (pun intended) libc namespace issues, using
wrapper .h files and asm labels to let internal calls resolve directly and
not be overridable or use the PLT. Then, apply that framework to most of
the functions in stdio.h, string.h, err.h, and wchar.h. Delete the
should-have-been-hidden-all-along _v?(err|warn)[cx]? symbols while here.

tests clean on i386, amd64, sparc64, powerpc, and mips64

naming feedback from kettenis@ and millert@
ok kettenis@

First pass at removing clauses 3 and 4 from NetBSD licenses.

Not sure what's more surprising: how long it took for NetBSD to
catch up to the rest of the BSDs (including UCB), or the amount of
code that NetBSD has claimed for itself without attributing to the
actual authors.

OK deraadt@

ARGH, forgot tags.

arm libc support. From NetBSD. currently supports softfloat.