[reference-types] Support passive elem segments (#3572)

Passive element segments do not belong to any table, so the link between
Table and elem needs to be weaker; i.e. an elem may have a table in case
of active segments, or simply be a collection of function references in
case of passive/declarative segments.

This PR takes Table::Segment out and turns it into a first class module
element just like tables and functions. It also implements early support
for parsing, printing, encoding and decoding passive/declarative elem
segments.

1 files changed, 4 insertions, 5 deletions

diff --git a/src/passes/opt-utils.h b/src/passes/opt-utils.h
index 0a67a7e1e..27a3c5c25 100644
--- a/src/passes/opt-utils.h
+++ b/src/passes/opt-utils.h
@@ -86,13 +86,12 @@ inline void replaceFunctions(PassRunner* runner,
   // replace direct calls
   FunctionRefReplacer(maybeReplace).run(runner, &module);
   // replace in table
-  for (auto& table : module.tables) {
-    for (auto& segment : table->segments) {
-      for (auto& name : segment.data) {
-        maybeReplace(name);
-      }
+  for (auto& segment : module.elementSegments) {
+    for (auto& name : segment->data) {
+      maybeReplace(name);
     }
   }
+
   // replace in start
   if (module.start.is()) {
     maybeReplace(module.start);