Unify imported and non-imported things (#1678)

Fixes #1649

This moves us to a single object for functions, which can be imported or nor, and likewise for globals (as a result, GetGlobals do not need to check if the global is imported or not, etc.). All imported things now inherit from Importable, which has the module and base of the import, and if they are set then it is an import.

For convenient iteration, there are a few helpers like

ModuleUtils::iterDefinedGlobals(wasm, [&](Global* global) {
  .. use global ..
});

as often iteration only cares about imported or defined (non-imported) things.

1 files changed, 5 insertions, 4 deletions

diff --git a/src/passes/PostEmscripten.cpp b/src/passes/PostEmscripten.cpp
index a7f0e6282..72c0d8808 100644
--- a/src/passes/PostEmscripten.cpp
+++ b/src/passes/PostEmscripten.cpp
@@ -92,11 +92,12 @@ struct PostEmscripten : public WalkerPass<PostWalker<PostEmscripten>> {
     optimizeMemoryAccess(curr->ptr, curr->offset);
   }
 
-  void visitCallImport(CallImport* curr) {
+  void visitCall(Call* curr) {
     // special asm.js imports can be optimized
-    auto* import = getModule()->getImport(curr->target);
-    if (import->module == GLOBAL_MATH) {
-      if (import->base == POW) {
+    auto* func = getModule()->getFunction(curr->target);
+    if (!func->imported()) return;
+    if (func->module == GLOBAL_MATH) {
+      if (func->base == POW) {
         if (auto* exponent = curr->operands[1]->dynCast<Const>()) {
           if (exponent->value == Literal(double(2.0))) {
             // This is just a square operation, do a multiply