Add TODO comments with link to issue for aarch64 reference types

build.rs

@@ -211,8 +211,8 @@ fn ignore(testsuite: &str, testname: &str, strategy: &str) -> bool {
 
             ("reference_types", "table_copy_on_imported_tables")
             | ("reference_types", "externref_id_function") => {
-                // Ignore if this isn't x64, because Cranelift only supports
-                // reference types on x64.
+                // TODO(#1886): Ignore if this isn't x64, because Cranelift only
+                // supports reference types on x64.
                 return env::var("CARGO_CFG_TARGET_ARCH").unwrap() != "x86_64";
             }
 

tests/all/main.rs

@@ -19,6 +19,6 @@ mod traps;
 mod use_after_drop;
 mod wast;
 
-// Cranelift only supports reference types on x64.
+// TODO(#1886): Cranelift only supports reference types on x64.
 #[cfg(target_arch = "x86_64")]
 mod gc;