Fix sharedness bug in inhabitable type fuzzer (#6807)

The code for collecting inhabitable types incorrectly considered shared,
non-nullable externrefs to be inhabitable, which disagreed with the code
for rewriting types to be inhabitable, which was correct, causing the
type fuzzer to report an error.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/tools/fuzzing/heap-types.cpp b/src/tools/fuzzing/heap-types.cpp
index 7eaf23701..e4d54ae07 100644
--- a/src/tools/fuzzing/heap-types.cpp
+++ b/src/tools/fuzzing/heap-types.cpp
@@ -1031,7 +1031,8 @@ bool isUninhabitable(Type type,
                      std::unordered_set<HeapType>& visited,
                      std::unordered_set<HeapType>& visiting) {
   if (type.isRef() && type.isNonNullable()) {
-    if (type.getHeapType().isBottom() || type.getHeapType() == HeapType::ext) {
+    if (type.getHeapType().isBottom() ||
+        type.getHeapType().isMaybeShared(HeapType::ext)) {
       return true;
     }
     return isUninhabitable(type.getHeapType(), visited, visiting);