Replace `RefIs` with `RefIsNull` (#5401)

* Replace `RefIs` with `RefIsNull`

The other `ref.is*` instructions are deprecated and expressible in terms of
`ref.test`. Update binary and text parsing to parse those instructions as
`RefTest` expressions. Also update the printing and emitting of `RefTest`
expressions to emit the legacy instructions for now to minimize test changes and
make this a mostly non-functional change. Since `ref.is_null` is the only
`RefIs` instruction left, remove the `RefIsOp` field and rename the expression
class to `RefIsNull`.

The few test changes are due to the fact that `ref.is*` instructions are now
subject to `ref.test` validation, and in particular it is no longer valid to
perform a `ref.is_func` on a value outside of the `func` type hierarchy.

2 files changed, 2 insertions, 26 deletions

diff --git a/test/example/c-api-kitchen-sink.c b/test/example/c-api-kitchen-sink.c
index de105d239..cc2c96538 100644
--- a/test/example/c-api-kitchen-sink.c
+++ b/test/example/c-api-kitchen-sink.c
@@ -1002,8 +1002,8 @@ void test_core() {
                                iIfF,
                                BinaryenTypeInt32()),
     // Reference types
-    BinaryenRefIs(module, BinaryenRefIsNull(), externrefExpr),
-    BinaryenRefIs(module, BinaryenRefIsNull(), funcrefExpr),
+    BinaryenRefIsNull(module, externrefExpr),
+    BinaryenRefIsNull(module, funcrefExpr),
     BinaryenSelect(
       module,
       temp10,
@@ -1014,15 +1014,6 @@ void test_core() {
     BinaryenRefEq(module,
                   BinaryenRefNull(module, BinaryenTypeNullref()),
                   BinaryenRefNull(module, BinaryenTypeNullref())),
-    BinaryenRefIs(module,
-                  BinaryenRefIsFunc(),
-                  BinaryenRefNull(module, BinaryenTypeNullref())),
-    BinaryenRefIs(module,
-                  BinaryenRefIsData(),
-                  BinaryenRefNull(module, BinaryenTypeNullref())),
-    BinaryenRefIs(module,
-                  BinaryenRefIsI31(),
-                  BinaryenRefNull(module, BinaryenTypeNullref())),
     BinaryenRefAs(module,
                   BinaryenRefAsNonNull(),
                   BinaryenRefNull(module, BinaryenTypeNullref())),
diff --git a/test/example/c-api-kitchen-sink.txt b/test/example/c-api-kitchen-sink.txt
index 1ee529eb3..51298d1a2 100644
--- a/test/example/c-api-kitchen-sink.txt
+++ b/test/example/c-api-kitchen-sink.txt
@@ -2004,21 +2004,6 @@ BinaryenFeatureAll: 126975
        )
       )
       (drop
-       (ref.is_func
-        (ref.null none)
-       )
-      )
-      (drop
-       (ref.is_data
-        (ref.null none)
-       )
-      )
-      (drop
-       (ref.is_i31
-        (ref.null none)
-       )
-      )
-      (drop
        (ref.as_non_null
         (ref.null none)
        )