[GC] Add Array operations (#3436)

array.new/get/set/len - pretty straightforward after structs and all the
infrastructure for them.

Also fixes validation of the unnecessary heapType param in the
text and binary formats in structs as well as arrays.

Fixes printing of packed types in type names, which emitted i32
for them. That broke when we emitted the same name for an array
of i8 and i32 as in the new testing here.

Also fix a bug in Field::operator< which was wrong for packed
types; again, this was easy to notice with the new testing.

1 files changed, 23 insertions, 6 deletions

diff --git a/src/wasm/wasm-stack.cpp b/src/wasm/wasm-stack.cpp
index 2e4e9d332..60c352c5d 100644
--- a/src/wasm/wasm-stack.cpp
+++ b/src/wasm/wasm-stack.cpp
@@ -1928,33 +1928,50 @@ void BinaryInstWriter::visitStructGet(StructGet* curr) {
   } else {
     op = BinaryConsts::StructGetU;
   }
-  o << int8_t(BinaryConsts::GCPrefix) << int8_t(op);
+  o << int8_t(BinaryConsts::GCPrefix) << U32LEB(op);
   parent.writeHeapType(heapType);
   o << U32LEB(curr->index);
 }
 
 void BinaryInstWriter::visitStructSet(StructSet* curr) {
-  o << int8_t(BinaryConsts::GCPrefix) << int8_t(BinaryConsts::StructSet);
+  o << int8_t(BinaryConsts::GCPrefix) << U32LEB(BinaryConsts::StructSet);
   parent.writeHeapType(curr->ref->type.getHeapType());
   o << U32LEB(curr->index);
 }
 
 void BinaryInstWriter::visitArrayNew(ArrayNew* curr) {
-  WASM_UNREACHABLE("TODO (gc): array.new");
+  o << int8_t(BinaryConsts::GCPrefix);
+  if (curr->isWithDefault()) {
+    o << U32LEB(BinaryConsts::ArrayNewDefaultWithRtt);
+  } else {
+    o << U32LEB(BinaryConsts::ArrayNewWithRtt);
+  }
+  parent.writeHeapType(curr->rtt->type.getHeapType());
 }
 
 void BinaryInstWriter::visitArrayGet(ArrayGet* curr) {
-  WASM_UNREACHABLE("TODO (gc): array.get");
+  auto heapType = curr->ref->type.getHeapType();
+  const auto& field = heapType.getArray().element;
+  int8_t op;
+  if (field.type != Type::i32 || field.packedType == Field::not_packed) {
+    op = BinaryConsts::ArrayGet;
+  } else if (curr->signed_) {
+    op = BinaryConsts::ArrayGetS;
+  } else {
+    op = BinaryConsts::ArrayGetU;
+  }
+  o << int8_t(BinaryConsts::GCPrefix) << U32LEB(op);
+  parent.writeHeapType(heapType);
 }
 
 void BinaryInstWriter::visitArraySet(ArraySet* curr) {
   o << int8_t(BinaryConsts::GCPrefix) << U32LEB(BinaryConsts::ArraySet);
-  WASM_UNREACHABLE("TODO (gc): array.set");
+  parent.writeHeapType(curr->ref->type.getHeapType());
 }
 
 void BinaryInstWriter::visitArrayLen(ArrayLen* curr) {
   o << int8_t(BinaryConsts::GCPrefix) << U32LEB(BinaryConsts::ArrayLen);
-  WASM_UNREACHABLE("TODO (gc): array.len");
+  parent.writeHeapType(curr->ref->type.getHeapType());
 }
 
 void BinaryInstWriter::emitScopeEnd(Expression* curr) {