PR/58748: Use '_SYSCALL_ERR' instead of 'jmp CERROR' for the hand-crafted
system calls (the regular system calls do this already). This is a noop
for amd64 and it is done for cosmetic reasons, but for i386 it produces
correct pic code.

Put missing END() markers to set ELF symbol size.

branches: 1.21.2;
Pass PICFLAGS down to cc-as-as and use __PIC__ to decide if it is small
vs big PIC mode. Retire -DPIC and -DBIGPIC.

branches: 1.20.6;
Mark __cerror as hidden and exploit that to simplify assembler.

branches: 1.19.2; 1.19.6;
Avoid calling a syscall when argument to sbrk(2) is zero.
OK by <ad>.

branches: 1.18.12;
If I686_LIBC is defined, make syscalls using the 'sysenter' instruction.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22280, verified by myself.

use canonical indirect jmp & call syntax to squelch new as(1) warning

branches: 1.15.2;
Use the SYSTRAP() macro more uniformly.

Thinko in previous: we do always use an internal name.

Add internal names for brk() and sbrk().

branches: 1.12.4;
Clean up.
* _REENTRANT is always defined.
* The vfork() stubs can use cerror.

Repair syscall stubs that were not updated when the cerror interface was
modified.

branches: 1.10.2;
Amend for the PLT fixes, things broke last night with the changes to SYS.h
and cerror.S. In particular, the syscalls in the files committed below were
broken.

* On architectures using ELF, and conditionally on those in transition, rename
_ASM_LABEL(cerror) and _ASM_LABEL(curbrk) to _C_LABEL(__cerror) and
_C_LABEL(__curbrk) (or their respective architecture-specific equivalents) to
avoid possible name clashes with identifiers used in user applications.
* Do the same for minbrk on all architectures to avoid a GCC-specific (and
on ELF architectures effectively useless) symbol reference renaming in MI code.

RCSID fixes: Always use the NetBSD rcsid and the macro RCSID() defined in
<machine/asm.h>; Also syscalls should be protected using the SYSLIBC_SCCS
define not LIBC_SCCS

Use trap gate to enter kernel.

Separate curbrk and mincrk.

Random cleanup.

SYS_brk --> SYS_break. Where's my axe?

More stylistic changes.

Move the old berkeley sccs id into the header comment like it is done
for other source files.

make an arch directory in libc, and move all machine dirs into it