Add support for the reference types proposal (#938)

* Add support for the reference types proposal

This commit adds support for the reference types proposal to wabt.
Namely it adds new opcodes like `table.{get,set,grow}` as well as adds a
new `anyref` type. These are plumbed throughout for various operations
in relatively simple fashions, no support was added for a subtyping
relationship between `anyref` and `anyfunc` just yet.

This also raises the restriction that multiple tables are disallowed,
allowing multiple tables to exist when `--enable-reference-types` is
passed.

* Allow nonzero table indices in `call_indirect`

Plumb support throughout for the `call_indirect` instruction (and
`return_call_indirect`) to work with multi-table modules according to
the reference types proposal.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/ir.cc b/src/ir.cc
index 52af00f1..70ca45c3 100644
--- a/src/ir.cc
+++ b/src/ir.cc
@@ -58,6 +58,8 @@ const char* ExprTypeName[] = {
   "MemoryInit",
   "MemorySize",
   "Nop",
+  "RefIsNull",
+  "RefNull",
   "Rethrow",
   "Return",
   "ReturnCall",
@@ -69,6 +71,10 @@ const char* ExprTypeName[] = {
   "TableCopy",
   "ElemDrop",
   "TableInit",
+  "TableGet",
+  "TableGrow",
+  "TableSize",
+  "TableSet",
   "Ternary",
   "Throw",
   "Try",