Add test cases for the command built-in, including its -v and -V options which

I'll commit real soon.

Count the number of found test cases instead of hard-coding them.  Allow an
arbitrary exit status.

tools/regression/bin/sh/builtins/command1.0

@@ -0,0 +1,5 @@
+# $FreeBSD$
+true() {
+	false
+}
+command true

tools/regression/bin/sh/builtins/command2.0

@@ -0,0 +1,3 @@
+# $FreeBSD$
+PATH=
+command -p cat < /dev/null

tools/regression/bin/sh/builtins/command3.0

@@ -0,0 +1,13 @@
+# $FreeBSD$
+command -v ls
+command -v true
+command -v /bin/ls
+
+fun() {
+}
+command -v fun
+command -v break
+command -v if
+
+alias foo=bar
+command -v foo

tools/regression/bin/sh/builtins/command3.0.stdout

@@ -0,0 +1,7 @@
+/bin/ls
+true
+/bin/ls
+fun
+break
+if
+alias foo='bar '

tools/regression/bin/sh/builtins/command4.127

@@ -0,0 +1,2 @@
+# $FreeBSD$
+command -v nonexisting

tools/regression/bin/sh/builtins/command5.0

@@ -0,0 +1,14 @@
+# $FreeBSD$
+command -V ls
+command -V true
+command -V /bin/ls
+
+fun() {
+}
+command -V fun
+command -V break
+command -V if
+command -V {
+
+alias foo=bar
+command -V foo

tools/regression/bin/sh/builtins/command5.0.stdout

@@ -0,0 +1,8 @@
+ls is /bin/ls
+true is a shell builtin
+/bin/ls is /bin/ls
+fun is a shell function
+break is a shell builtin
+if is a shell keyword
+{ is a shell keyword
+foo is an alias for bar 

tools/regression/bin/sh/builtins/command6.127

@@ -0,0 +1,2 @@
+# $FreeBSD$
+command -V nonexisting

tools/regression/bin/sh/builtins/command6.127.stdout

@@ -0,0 +1 @@
+nonexisting: not found

tools/regression/bin/sh/regress.sh

@@ -1,7 +1,5 @@
 # $FreeBSD$
 
-echo '1..42'
-
 COUNTER=1
 
 do_test() {
@@ -31,7 +29,9 @@ do_test() {
 	rm tmp.stdout tmp.stderr
 }
 
-TESTS=$(find -s . -name "*.[01]")
+TESTS=$(find -Es . -regex ".*\.[0-9]+")
+printf "1..%d\n" $(echo ${TESTS} | wc -w)
+
 for i in ${TESTS} ; do
 	do_test ${i} ${i##*.}
 done