Add lots of checks for out of memory (re: 0ce0b671)

Huge typeset -L/-R adjustment length values were still causing
crashses on sytems with not enough memory. They should error out
gracefully instead of crashing.

This commit adds out of memory checks to all malloc/calloc/realloc
calls that didn't have them (which is all but two or three).

The stkalloc/stakalloc calls don't need the checks; it has
automatic checking, which is done by passing a pointer to the
outofspace() function to the stakinstall() call in init.c.

src/lib/libast/include/error.h:
- Change the ERROR_PANIC exit status value from ERROR_LEVEL (255)
  to 77, which is what it is supposed to be according to the libast
  error.3 manual page. Exit statuses > 128 for anything else than
  signals are not POSIX compliant and may cause misbehaviour.

src/cmd/ksh93/include/defs.h,
src/cmd/ksh93/sh/init.c:
- To facilitate consistency, add a simple extern sh_outofmemory()
  function that throws an ERROR_PANIC "out of memory".

src/cmd/ksh93/include/shell.h,
src/cmd/ksh93/data/builtins.c:
- Remove now-redundant e_nospace[] extern message; it is now only
  used in one place so it might as well be a string literal in
  sh_outofmemory().

All other changed files:
- Verify the result of all malloc/calloc/realloc calls and call
  sh_outofmemory() if they fail.

src/cmd/ksh93/sh/init.c

@@ -219,13 +219,18 @@ static int		shlvl;
 static int		rand_shift;
 
 
+void sh_outofmemory(void)
+{
+	errormsg(SH_DICT,ERROR_PANIC,"out of memory");
+}
+
 /*
  * out of memory routine for stak routines
  */
 static char *nospace(int unused)
 {
 	NOT_USED(unused);
-	errormsg(SH_DICT,ERROR_exit(3),e_nospace);
+	sh_outofmemory();
 	return(NIL(char*));
 }
 
@@ -313,6 +318,8 @@ static Sfdouble_t nget_optindex(register Namval_t* np, Namfun_t *fp)
 static Namfun_t *clone_optindex(Namval_t* np, Namval_t *mp, int flags, Namfun_t *fp)
 {
 	Namfun_t *dp = (Namfun_t*)malloc(sizeof(Namfun_t));
+	if(!dp)
+		sh_outofmemory();
 	memcpy((void*)dp,(void*)fp,sizeof(Namfun_t));
 	mp->nvalue.lp = np->nvalue.lp;
 	dp->nofree = 0;
@@ -440,6 +447,8 @@ static void put_cdpath(register Namval_t* np,const char *val,int flags,Namfun_t
 			register int c;
 			char *state[4];
 			sh_lexstates[ST_BEGIN] = state[0] = (char*)malloc(4*(1<<CHAR_BIT));
+			if(!state[0])
+				sh_outofmemory();
 			memcpy(state[0],sh_lexrstates[ST_BEGIN],(1<<CHAR_BIT));
 			sh_lexstates[ST_NAME] = state[1] = state[0] + (1<<CHAR_BIT);
 			memcpy(state[1],sh_lexrstates[ST_NAME],(1<<CHAR_BIT));
@@ -810,6 +819,8 @@ void sh_setmatch(Shell_t *shp,const char *v, int vsize, int nmatch, regoff_t mat
 				mp->match = (int*)realloc(mp->match,i+vsize+1);
 			else
 				mp->match = (int*)malloc(i+vsize+1);
+			if(!mp->match)
+				sh_outofmemory();
 			mp->vsize = i+vsize+1;
 		}
 		mp->val =  ((char*)mp->match)+i; 
@@ -862,6 +873,8 @@ static char* get_match(register Namval_t* np, Namfun_t *fp)
 		mp->rval[i] = 0;
 	}
 	mp->rval[i] = (char*)malloc(n+1);
+	if(!mp->rval[i])
+		sh_outofmemory();
 	mp->lastsub[i] = sub;
 	memcpy(mp->rval[i],val,n);
 	mp->rval[i][n] = 0;
@@ -934,6 +947,8 @@ static void math_init(Shell_t *shp)
 	char		*name;
 	int		i;
 	shp->mathnodes = (char*)calloc(1,MAX_MATH_ARGS*(NV_MINSZ+5));
+	if(!shp->mathnodes)
+		sh_outofmemory();
 	name = shp->mathnodes+MAX_MATH_ARGS*NV_MINSZ;
 	for(i=0; i < MAX_MATH_ARGS; i++)
 	{
@@ -1064,6 +1079,8 @@ static int newconf(const char *name, const char *path, const char *value)
     {
 	int i;
 	char *cp = (char*)malloc(ST_NONE*(1<<CHAR_BIT));
+	if(!cp)
+		sh_outofmemory();
 	for(i=0; i < ST_NONE; i++)
 	{
 		a2e(cp,sh_lexrstates[i]);
@@ -1714,6 +1731,8 @@ static void stat_init(Shell_t *shp)
 	sp->numnodes = nstat;
 	sp->nodes = (char*)(sp+1);
 	shgd->stats = (int*)calloc(sizeof(int),nstat);
+	if(!shgd->stats)
+		sh_outofmemory();
 	sp->sh = shp;
 	for(i=0; i < nstat; i++)
 	{
@@ -1878,6 +1897,8 @@ Dt_t *sh_inittree(Shell_t *shp,const struct shtable2 *name_vals)
 	for(tp=name_vals;*tp->sh_name;tp++)
 		n++;
 	np = (Namval_t*)calloc(n,sizeof(Namval_t));
+	if(!np)
+		sh_outofmemory();
 	if(!shgd->bltin_nodes)
 	{
 		shgd->bltin_nodes = np;