Add qsort test

tests/Makefile

@@ -53,6 +53,7 @@ EXPECT_NAMES=\
 	stdlib/div \
 	stdlib/env \
 	stdlib/mkostemps \
+	stdlib/qsort \
 	stdlib/rand \
 	stdlib/rand48 \
 	stdlib/random \

tests/expected/bins_static/stdlib/qsort.stdout

+Before: 23 16 8 4 42 15 
+After: 4 8 15 16 23 42 

tests/stdlib/qsort.c

+#include <stdio.h>
+#include <stdlib.h>
+
+#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
+
+int values[] = { 23, 16, 8, 4, 42, 15 };
+
+int cmpfunc (const void * a_ptr, const void * b_ptr) {
+    int a = *(const int *)a_ptr;
+    int b = *(const int *)b_ptr;
+    return a - b;
+}
+
+int main () {
+    int i;
+
+    printf("Before: ");
+    for(i = 0; i < ARRAY_SIZE(values); i++) {
+        printf("%d ", values[i]);
+    }
+    printf("\n");
+
+    qsort(values, ARRAY_SIZE(values), sizeof(int), cmpfunc);
+
+    printf("After: ");
+    for(i = 0; i < ARRAY_SIZE(values); i++) {
+        printf("%d ", values[i]);
+    }
+    printf("\n");
+
+    return 0;
+}