PR/45989: Martin Husemann: lint invocation does include -w only on i386

- turn lint -w for all the platforms after fixing the lint warnings.
- add _DIAGASSERTS() for casts that would assign values to types that
would not fit.
- change types, add casts
- change into ansii prototypes
- turn on _DIAGNOSTIC for libc (during current, to be eliminated for release
builds)

approved by core@

branches: 1.13.56;
netbsd.org->NetBSD.org

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

Add l64a_r(), a reentrant version of l64a(); found in the Multithreading
Extension of SVID4.

delint

Per XPG4.2, if the `value' argument evaluates to 0L, don't return a NULL
pointer but a pointer to an empty string.

If port provides __weak_alias(), provide an Standard C and POSIX pure
identifier namespace by renaming non standard functions and variables
such that they have a leading underscore. The library will use those
names internally. Weak aliases are used to provide the original names
to the API.

This is only the first part of this change. It is most of the functions
which are implemented in C for all NetBSD ports. Subsequent changes are
to add the same support to the remaining C files, to assembly files, and
to the automagically generated assembly source used for system calls.
When all of the above is done, ports with weak alias support should add
a definition for __weak_alias to <sys/cdefs.h>.

Add local.h for local prototypes.
Fix namespace issues for strtoq and strtouq
Fix gcc warnings.
Fix RCSID's

branches: 1.4.4;
Winning Strategies has placed this code in the public domain.

remove unneeded "#include <stddef.h>"

Fix spelling error in Copyright notice

Added 1170's a64l() & l64a() functions.