stk(3): fix argument type of exception callback function

The callback function for malloc(3) failure in the stk(3) routines
(which can be specified using stkinstall() and is set to nomemory()
in init.c) uses a size argument of type int. That's a type mismatch
with all the other size arguments and variables in stk(3) which use
size_t, an unsigned type that may be larger than int.

This is all quite inconsequential as nothing in our code base (or
in the complete old AT&T AST code base) actually uses that size for
anything, but it's still wrong, so this corrects the interface.

With this very minor API change, let's bump the libast API version
to 20220801, the date of the upcoming ksh 93u+m 1.0.0 release. :)

The ksh93/sh/init.c nomemory() function now reports the size that
could not be allocated, just because it can.

src/cmd/ksh93/include/defs.h

@@ -30,8 +30,8 @@
 #endif
 
 #include	<ast.h>
-#if !defined(AST_VERSION) || AST_VERSION < 20220208
-#error libast version 20220208 or later is required
+#if !defined(AST_VERSION) || AST_VERSION < 20220801
+#error libast version 20220801 or later is required
 #endif
 #if !_lib_fork
 #error In 2021, ksh joined the 21st century and started requiring fork(2).

src/cmd/ksh93/sh/init.c

@@ -222,12 +222,11 @@ static int		shlvl;
 static int		rand_shift;
 
 /*
- * out of memory routine for stak routines
+ * Exception callback routine for stk(3)/stak(3) and sh_*alloc wrappers.
  */
-static noreturn char *nomemory(int unused)
+static noreturn char *nomemory(size_t s)
 {
-	NOT_USED(unused);
-	errormsg(SH_DICT, ERROR_SYSTEM|ERROR_PANIC, "out of memory");
+	errormsg(SH_DICT, ERROR_SYSTEM|ERROR_PANIC, "out of memory (needed %llu bytes)", (uintmax_t)s);
 	UNREACHABLE();
 }
 
@@ -239,7 +238,7 @@ void *sh_malloc(size_t size)
 {
 	void *cp = malloc(size);
 	if(!cp)
-		nomemory(0);
+		nomemory(size);
 	return(cp);
 }
 
@@ -247,7 +246,7 @@ void *sh_realloc(void *ptr, size_t size)
 {
 	void *cp = realloc(ptr, size);
 	if(!cp)
-		nomemory(0);
+		nomemory(size);
 	return(cp);
 }
 
@@ -255,7 +254,7 @@ void *sh_calloc(size_t nmemb, size_t size)
 {
 	void *cp = calloc(nmemb, size);
 	if(!cp)
-		nomemory(0);
+		nomemory(size);
 	return(cp);
 }
 
@@ -263,7 +262,7 @@ char *sh_strdup(const char *s)
 {
 	char *dup = strdup(s);
 	if(!dup)
-		nomemory(0);
+		nomemory(strlen(s)+1);
 	return(dup);
 }
 
@@ -271,7 +270,7 @@ void *sh_memdup(const void *s, size_t n)
 {
 	void *dup = memdup(s, n);
 	if(!dup)
-		nomemory(0);
+		nomemory(n);
 	return(dup);
 }
 
@@ -279,7 +278,7 @@ char *sh_getcwd(void)
 {
 	char *cwd = getcwd(NIL(char*), 0);
 	if(!cwd && errno==ENOMEM)
-		nomemory(0);
+		nomemory(PATH_MAX);
 	return(cwd);
 }