msh: fix "while...continue" bug 3884.

diff --git a/shell/msh_test/msh-execution/many_continues.right b/shell/msh_test/msh-execution/many_continues.right
new file mode 100644
index 0000000..d86bac9
--- /dev/null
+++ b/shell/msh_test/msh-execution/many_continues.right
@@ -0,0 +1 @@
+OK