Don't use "NULL" to talk about null-terminated strings.

The C standard seems to be inconsistent about dash vs. space. Old
text uses dash, Annex K uses space. I'll let wizd(8) to sort that
out.

Reinstate __getdelim which does no locking.
Callers are now required to FLOCKFILE so they can operate on fp as well.

__getdelim works on strings up to SIZE_MAX - 2 and returns 0 on EOF.
getdelim works on strings up to SSIZE_MAX and returns -1 on EOF.
__fgetstr is now just a wrapper around __getdelim and ensures that
the buffer doesn't overflow the one provided by FILE.
__slbexpand is now static in fgetwln as it is the only consumer of that func.

After discussion with christos, turn fgetstr() into an internal function.
Its API in inherently non-threadsafe (and it depends on certain properties
of the underlying stdio implementation), so it shouldn't be a first-class
function for general use, polluting the application namespace.
Also remove the FLOCKFILE() code from it - this is under control of the
calling function now.
(XXX I'm not sure whether the FLOCKFILE() should be kept in fgetln(),
this function cannot be used in multiple threads anyway. It doesn't
hurt much, and it might prevent corruption of internal FILE structures.)

Add a generalized version of fgetln that can stop at an arbitrary delimiter,
and implement fgetln on top of that.

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

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

Merge the nathanw_sa branch.

branches: 1.10.6;
Delint.
Remove trailing ; from uses of __weak_alias(). The macro inserts this if
needed.

back out the #ifdef _DIAGNOSTIC argument checks; too many people complained.
_DIAGASSERT() is still retained.

* use _DIAGASSERT() to check pointer arguments against NULL and file
descriptors against -1 (as appropriate).
* add actual checks which to detect stuff that would trigger_DIAGASSERT(),
and attempt to return a sane error condition.
* knf some code
* remove some `register' decls.

the first two items result in the addition of code similar to the
following in various functions:

_DIAGASSERT(path != NULL)
#ifdef _DIAGNOSTIC
if (path == NULL) {
errno = EFAULT;
return (-1);
}
#endif

delint

Need an internal name for fgetln().

remove obsolete register declarations

Use FLOCKFILE() and FUNLOCKFILE() macros from reentrant.h so that stdio
can be made thread-safe.

Fix RCSID's
Fix gcc warnings.
Add prototypes for functions that were declared in more than one place
to local.h or extern.h and use that instead.

branches: 1.2.6;
Merged with 4.4lite.
Changed to conform to NetBSD's new RCS Id convention.

branches: 1.1.1;
rename fgetline() and sharpen axe for bostic...