SI-7231 Fix assertion when adapting Null type to Array type

GenICode was doing a sanity check when adapting an expression of type
Null to something else. It was just doing the wrong one. Instead of
checking whether the result expression type was a reference type it
was checking to see if it was an class reference type. This commit fixes
that and adds a test to make sure both forms of adaptation work as
expected.

1 files changed, 2 insertions, 0 deletions

diff --git a/test/files/run/t7231.check b/test/files/run/t7231.check
new file mode 100644
index 0000000000..c1e4b6c175
--- /dev/null
+++ b/test/files/run/t7231.check
@@ -0,0 +1,2 @@
+null
+null