[GC] Fix casts of non-GC data (#3483)

The code previously assumed it could always call getGCData, but
that assumes the input is an array or a struct. It could also be an
anyref etc. that contains something other than GC data.

1 files changed, 11 insertions, 0 deletions

diff --git a/test/passes/Oz_fuzz-exec_all-features.wast b/test/passes/Oz_fuzz-exec_all-features.wast
index 78313267c..7d586cffc 100644
--- a/test/passes/Oz_fuzz-exec_all-features.wast
+++ b/test/passes/Oz_fuzz-exec_all-features.wast
@@ -179,4 +179,15 @@
    )
   )
  )
+ (func "cast-null-anyref-to-gc"
+  ;; a null anyref is a literal which is not even of GC data, as it's not an
+  ;; array or a struct, so our casting code should not assume it is. it is ok
+  ;; to try to cast it, and the result should be 0.
+  (call $log
+   (ref.test $struct
+    (ref.null any)
+    (rtt.canon $struct)
+   )
+  )
+ )
 )