ash: add all hush parsing tests to ast tests

All pass.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash_test/ash-parsing/escape4.tests b/shell/ash_test/ash-parsing/escape4.tests
new file mode 100755
index 0000000..df8bf0a
--- /dev/null
+++ b/shell/ash_test/ash-parsing/escape4.tests
@@ -0,0 +1,6 @@
+i\
+f tr\
+ue; th\
+en echo "O\
+k"; fi; echo "\
+End"
\ No newline at end of file