qsort: allow usize-sized arrays.

As part of the transition to 64 bit userspace
APIs, we need to make our libc functions which
take arrays all accept and deal with large sizes.

This does the work for qsort.

sys/src/libc/port/qsort.c

@@ -8,12 +8,12 @@ typedef
 struct
 {
 	int	(*cmp)(void*, void*);
-	void	(*swap)(char*, char*, long);
-	long	es;
+	void	(*swap)(char*, char*, usize);
+	usize	es;
 } Sort;
 
 static	void
-swapb(char *i, char *j, long es)
+swapb(char *i, char *j, usize es)
 {
 	char c;
 
@@ -27,7 +27,7 @@ swapb(char *i, char *j, long es)
 }
 
 static	void
-swapi(char *ii, char *ij, long es)
+swapi(char *ii, char *ij, usize es)
 {
 	long *i, *j, c;
 
@@ -42,9 +42,9 @@ swapi(char *ii, char *ij, long es)
 }
 
 static	char*
-pivot(char *a, long n, Sort *p)
+pivot(char *a, usize n, Sort *p)
 {
-	long j;
+	usize j;
 	char *pi, *pj, *pk;
 
 	j = n/6 * p->es;
@@ -69,9 +69,9 @@ pivot(char *a, long n, Sort *p)
 }
 
 static	void
-qsorts(char *a, long n, Sort *p)
+qsorts(char *a, usize n, Sort *p)
 {
-	long j, es;
+	usize j, es;
 	char *pi, *pj, *pn;
 
 	es = p->es;
@@ -111,7 +111,7 @@ qsorts(char *a, long n, Sort *p)
 }
 
 void
-qsort(void *va, long n, long es, int (*cmp)(void*, void*))
+qsort(void *va, usize n, usize es, int (*cmp)(void*, void*))
 {
 	Sort s;