ash: support for && and || in [[ expr ]]; add testsuite checks

diff --git a/shell/ash_test/ash-arith/arith-bash1.tests b/shell/ash_test/ash-arith/arith-bash1.tests
new file mode 100755
index 0000000..b37b730
--- /dev/null
+++ b/shell/ash_test/ash-arith/arith-bash1.tests
@@ -0,0 +1,5 @@
+# checks for [[ ]]
+
+# && and ||
+[[ a && "" ]]; echo $?
+[[ a || "" ]]; echo $?