[threads] ref.i31_shared (#6735)

Implement `ref.i31_shared` the new instruction for creating references
to shared i31s. Implement binary and text parsing and emitting as well
as interpretation. Copy the upstream spec test for i31 and modify it so
that all the heap types are shared. Comment out some parts that we do
not yet support.

1 files changed, 5 insertions, 1 deletions

diff --git a/src/passes/Print.cpp b/src/passes/Print.cpp
index 2e9800775..ede49ab38 100644
--- a/src/passes/Print.cpp
+++ b/src/passes/Print.cpp
@@ -2076,7 +2076,11 @@ struct PrintExpressionContents
     o << std::max(curr->tuple->type.size(), size_t(2)) << " ";
     o << curr->index;
   }
-  void visitRefI31(RefI31* curr) { printMedium(o, "ref.i31"); }
+  void visitRefI31(RefI31* curr) {
+    bool shared =
+      curr->type != Type::unreachable && curr->type.getHeapType().isShared();
+    printMedium(o, shared ? "ref.i31_shared" : "ref.i31");
+  }
   void visitI31Get(I31Get* curr) {
     printMedium(o, curr->signed_ ? "i31.get_s" : "i31.get_u");
   }