Mark __cerror as hidden to avoid using the PLT. This is required for new
binutils where the PLT stubs now use %t1 (%r22) which is used to pass
the errno to __cerror.

Add a space before any non-nullified instruction. NFCI.

Remove clause 3 and 4 from TNF licenses

replace these placeholders with real implementations.
translated from the mips version.

Add a cerror.S and re-work various syscalls and SYS.h to use __cerror.

With help from the OpenBSD version of SYS.h.

Update to new assmbler needs. Add getcontext.S stub.

Changes to allow libc to compile as PIC on the hppa.

Added hppa support (some of it incomplete) to lib/csu, lib/libc,
and lib/libkvm.