[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, 3 insertions, 5 deletions

diff --git a/src/passes/RemoveImports.cpp b/src/passes/RemoveImports.cpp
index 10a885586..be41717f4 100644
--- a/src/passes/RemoveImports.cpp
+++ b/src/passes/RemoveImports.cpp
@@ -49,11 +49,9 @@ struct RemoveImports : public WalkerPass<PostWalker<RemoveImports>> {
       *curr, [&](Function* func) { names.push_back(func->name); });
     // Do not remove names referenced in a table
     std::set<Name> indirectNames;
-    for (auto& table : curr->tables) {
-      for (auto& segment : table->segments) {
-        for (auto& name : segment.data) {
-          indirectNames.insert(name);
-        }
+    for (auto& segment : curr->elementSegments) {
+      for (auto& name : segment->data) {
+        indirectNames.insert(name);
       }
     }
     for (auto& name : names) {