Multivalue type creation and inspection (#2459)

Adds the ability to create multivalue types from vectors of concrete value
types. All types are transparently interned, so their representation is still a
single uint32_t. Types can be extracted into vectors of their component parts,
and all the single value types expand into vectors containing themselves.

Multivalue types are not yet used in the IR, but their creation and inspection
functionality is exposed and tested in the C and JS APIs.

Also makes common type predicates methods of Type and improves the ergonomics of
type printing.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/passes/CodeFolding.cpp b/src/passes/CodeFolding.cpp
index d60bc76d1..818bb33b8 100644
--- a/src/passes/CodeFolding.cpp
+++ b/src/passes/CodeFolding.cpp
@@ -139,7 +139,7 @@ struct CodeFolding : public WalkerPass<ControlFlowWalker<CodeFolding>> {
       // elements out of it if there is a value being returned)
       Block* parent = controlFlowStack.back()->dynCast<Block>();
       if (parent && curr == parent->list.back() &&
-          !isConcreteType(parent->list.back()->type)) {
+          !parent->list.back()->type.isConcrete()) {
         breakTails[curr->name].push_back(Tail(curr, parent));
       } else {
         unoptimizables.insert(curr->name);
@@ -189,7 +189,7 @@ struct CodeFolding : public WalkerPass<ControlFlowWalker<CodeFolding>> {
       return;
     }
     // we can't optimize a fallthrough value
-    if (isConcreteType(curr->list.back()->type)) {
+    if (curr->list.back()->type.isConcrete()) {
       return;
     }
     auto iter = breakTails.find(curr->name);