ash: fix a bug where redirection fds were not closed afterwards.
optimize close+fcntl(DUPFD) into dup2. add testsuites.
function old new delta
copyfd 47 68 +21
argstr 1311 1298 -13
popredir 148 131 -17
redirect 1139 1107 -32
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/3 up/down: 21/-62) Total: -41 bytes
diff --git a/shell/ash_test/ash-redir/redir3.right b/shell/ash_test/ash-redir/redir3.right
new file mode 100644
index 0000000..fd641a8
--- /dev/null
+++ b/shell/ash_test/ash-redir/redir3.right
@@ -0,0 +1,3 @@
+TEST
+./redir3.tests: line 4: 9: Bad file descriptor
+Output to fd#9: 1