Test char to int conversion.

tests/printf_test.aer

@@ -22,6 +22,7 @@ class Program {
 	private void testNumbers() {
 		printf("%%b = '%b'\n", $this->n);
 		printf("%%c = '%c'\n", $this->c);
+		printf("%%d = '%d'\n", $this->c);
 		printf("%%d = '%d'\n", $this->n);
 		printf("%%e = '%e'\n", $this->n);
 		printf("%%u = '%u'\n", $this->n);

tests/printf_test.exp

@@ -6,6 +6,7 @@
 [many monke]
 %b = '10100111101010011010101101'
 %c = 'A'
+%d = '65'
 %d = '43951789'
 %e = '4.395179e+07'
 %u = '43951789'