awk: unbreak "cmd" | getline

function                                             old     new   delta
evaluate                                            3337    3343      +6

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

testsuite/awk.tests

@@ -455,4 +455,9 @@ testing "awk print + redirect" \
 	"STDERR %s\n" \
 	'' ''
 
+testing "awk \"cmd\" | getline" \
+	"awk 'BEGIN { \"echo HELLO\" | getline; print }'" \
+	"HELLO\n" \
+	'' ''
+
 exit $FAILCOUNT