new option to auto-close varassign redirs; fixed some new parser error reporting issues

tests/comsub-eof.right

@@ -5,7 +5,6 @@ hi
 hi
 ./comsub-eof3.sub: line 4: warning: here-document at line 1 delimited by end-of-file (wanted `EOF')
 ./comsub-eof3.sub: line 5: unexpected EOF while looking for matching `)'
-./comsub-eof3.sub: line 5: unexpected EOF while looking for matching `)'
 ./comsub-eof4.sub: line 3: warning: here-document at line 1 delimited by end-of-file (wanted `EOF')
 contents
 ./comsub-eof5.sub: line 4: warning: here-document at line 2 delimited by end-of-file (wanted `)')

tests/posixexp.right

@@ -286,4 +286,3 @@ argv[1] = <"A">
 argv[1] = <A>
 argv[1] = <A>
 ./posixexp.tests: line 97: unexpected EOF while looking for matching `}'
-./posixexp.tests: line 98: syntax error: unexpected end of file

tests/shopt.right

@@ -53,6 +53,7 @@ shopt -s promptvars
 shopt -u restricted_shell
 shopt -u shift_verbose
 shopt -s sourcepath
+shopt -u varredir_close
 shopt -u xpg_echo
 --
 shopt -u huponexit
@@ -112,6 +113,7 @@ shopt -u nullglob
 shopt -u progcomp_alias
 shopt -u restricted_shell
 shopt -u shift_verbose
+shopt -u varredir_close
 shopt -u xpg_echo
 --
 autocd         	off
@@ -154,6 +156,7 @@ nullglob       	off
 progcomp_alias 	off
 restricted_shell	off
 shift_verbose  	off
+varredir_close 	off
 xpg_echo       	off
 --
 set +o allexport

tests/vredir.right

@@ -98,3 +98,4 @@ swizzle ()
     exec {stdin}<&${fd[0]}-;
     exec {stdout}>&${fd[1]}-
 }
+./vredir8.sub: line 12: $fd: Bad file descriptor

tests/vredir.tests

@@ -57,5 +57,6 @@ ${THIS_SH} ./vredir5.sub
 ${THIS_SH} ./vredir6.sub
 
 ${THIS_SH} ./vredir7.sub
+${THIS_SH} ./vredir8.sub
 
 exit 0

tests/vredir8.sub

@@ -0,0 +1,13 @@
+# test varredir_close
+
+: {fd}<>/dev/null
+
+echo redir 1 >&$fd
+exec {fd}>&-
+
+shopt -s varredir_close
+
+: {fd}<>/dev/tty
+
+echo redir 2 >&$fd
+exec {fd}>&-