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/escape1.right b/shell/ash_test/ash-parsing/escape1.right
new file mode 100644
index 0000000..1899b87
--- /dev/null
+++ b/shell/ash_test/ash-parsing/escape1.right
@@ -0,0 +1,4 @@
+\
+a\b
+\\
+c\\d