[Wasm GC] Take advantage of immutable struct fields in effects.h (#4240)

This is the easy part of using immutability more: Just note immutable
fields as such when we read from them, and then a write to a struct
does not interfere with such reads. That is, only a read from a mutable
field can notice the effect of a write.

1 files changed, 2 insertions, 1 deletions

diff --git a/test/example/cpp-unit.cpp b/test/example/cpp-unit.cpp
index 961013bc3..7c32478c6 100644
--- a/test/example/cpp-unit.cpp
+++ b/test/example/cpp-unit.cpp
@@ -611,7 +611,8 @@ void test_effects() {
     assert_equal(effects.trap, true);
     assert_equal(effects.readsArray, true);
     assert_equal(effects.writesArray, true);
-    assert_equal(effects.readsStruct, false);
+    assert_equal(effects.readsMutableStruct, false);
+    assert_equal(effects.readsImmutableStruct, false);
     assert_equal(effects.writesStruct, false);
   }
 }