Assume C89.

* Makefile (GCC_DEBUG_FLAGS): Modernize for GCC 4.6.3 x86.
* asctime.c (asctime_r, asctime):
* date.c (main, dogmt, reset, wildinput, nondigit, oops, display)
(timeout, sametm, netsettime):
* difftime.c (difftime):
* ialloc.c (icatalloc, icpyalloc):
* localtime.c (detzcode, detzcode64, differ_by_repeat)
(tzload, typesequiv, getzname, getnum, getsecs, getoffset)
(getrule, transtime, tzparse, gmtload, tzsetwall, tzset)
(localsub, localtime, localtime_r, gmtsub, gmtime, gmtime_r)
(offtime, leaps_thru_end_of, timesub, ctime, ctime_r)
(increment_overflow, long_increment_overflow)
(normalize_overflow, long_normalize_overflow, tmcomp, time2sub)
(time2, time1, mktime, timelocal, timegm, timeoff, gtime)
(leapcorr, time2posix, posix2time):
* scheck.c (scheck):
* strftime.c (strftime, _fmt, _conv, _add, _yconv, _loc):
* zdump.c (my_localtime, abbrok, usage, main, yeartot)
(delta, abbr, dumptime):
* zic.c (memcheck, eats, eat, error, warning, main)
(dolink, itsdir, rcomp, associate, infile, gethms, inrule)
(inzone, inzcont, inzsub, inleap, inlink, rulesub, convert)
(convert64, puttzcode, puttzcode64, atcomp, is32, writezone, DO)
(doabbr, updateminmax, stringoffset, stringrule, stringzone)
(outzone, addtt, addtype, leapadd, yearistype, lowerit, ciequal)
(itsabbr, byword, getfields, oadd, tadd, rpytime, newabbr)
(mkdirs, eitol):
Assume C89 or better.  Mostly this consists of using function
prototypes.  In a few places, prototypes are required for
portability to hosts where time_t does not promote to itself and
where a preceding prototype does not override a definition.  But
while we're at it we might as well be consistent: it's safe to
assume at-least-C89 these days.
* ialloc.c (nonzero, imalloc, icalloc, irealloc, ifree, icfree):
Remove; no longer needed now that we assume C89 or better.
All callers changed to use malloc, calloc, realloc, free.
* localtime.c (getzname, getqzname, leaps_thru_end_of, transtime):
* zdump.c (delta, yeartot):
* zic.c (eitol):
Now pure.
* private.h, zdump.c (ATTRIBUTE_PURE): New macro.
* private.h (icalloc, imalloc, irealloc, icfree, ifree): Remove decls.
* zic.c: Remove no-longer-necessary forward decls.
(max_time, min_time): Now const.
(setboundaries): Remove.

ialloc.c

@@ -7,39 +7,8 @@
 
 #include "private.h"
 
-#define nonzero(n)	(((n) == 0) ? 1 : (n))
-
 char *
-imalloc(n)
-const int	n;
-{
-	return malloc((size_t) nonzero(n));
-}
-
-char *
-icalloc(nelem, elsize)
-int	nelem;
-int	elsize;
-{
-	if (nelem == 0 || elsize == 0)
-		nelem = elsize = 1;
-	return calloc((size_t) nelem, (size_t) elsize);
-}
-
-void *
-irealloc(pointer, size)
-void * const	pointer;
-const int	size;
-{
-	if (pointer == NULL)
-		return imalloc(size);
-	return realloc((void *) pointer, (size_t) nonzero(size));
-}
-
-char *
-icatalloc(old, new)
-char * const		old;
-const char * const	new;
+icatalloc(char *const old, const char *const new)
 {
 	register char *	result;
 	register int	oldsize, newsize;
@@ -50,31 +19,14 @@ const char * const	new;
 	else if (newsize == 0)
 		return old;
 	else	oldsize = strlen(old);
-	if ((result = irealloc(old, oldsize + newsize + 1)) != NULL)
+	if ((result = realloc(old, oldsize + newsize + 1)) != NULL)
 		if (new != NULL)
 			(void) strcpy(result + oldsize, new);
 	return result;
 }
 
 char *
-icpyalloc(string)
-const char * const	string;
+icpyalloc(const char *const string)
 {
-	return icatalloc((char *) NULL, string);
-}
-
-void
-ifree(p)
-char * const	p;
-{
-	if (p != NULL)
-		(void) free(p);
-}
-
-void
-icfree(p)
-char * const	p;
-{
-	if (p != NULL)
-		(void) free(p);
+	return icatalloc(NULL, string);
 }