Add tests for stdlib

tests/stdlib_isupper_islower.c

@@ -0,0 +1,27 @@
+#include "stdlib.h"
+
+#define NULL 0x00
+
+int main(void)
+{
+  const char *uptest = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+  const char *lowtest = "abcdefghijklmnopqrstuvwcyz";
+  char *ptr = NULL;
+
+  for ( ptr = (char *)uptest; *ptr != '\0' ; ptr++ ) {
+    if ( isupper((int)*ptr) != 1 ) return (int)(ptr - uptest);
+  }
+  for ( ptr = (char *)lowtest; *ptr != '\0' ; ptr++ ) {
+    if ( isupper((int)*ptr) != 0 ) return (int)(26 + (ptr - lowtest));
+  }
+
+
+  for ( ptr = (char *)lowtest; *ptr != '\0' ; ptr++ ) {
+    if ( islower((int)*ptr) != 1 ) return (int)(52 + (ptr - uptest));
+  }
+  for ( ptr = (char *)uptest; *ptr != '\0' ; ptr++ ) {
+    if ( islower((int)*ptr) != 0 ) return (int)(78 + (ptr - lowtest));
+  }
+
+  return 0;
+}