handle try catch

Author: HerrCai0907

src/passes/TailCall.cpp

@@ -8,7 +8,7 @@ namespace wasm {
 
 namespace {
 
-struct Finder : PostWalker<Finder> {
+struct Finder : TryDepthWalker<Finder> {
   std::vector<Call*> tailCalls;
   std::vector<CallIndirect*> tailCallIndirects;
   void visitFunction(Function* curr) { checkTailCall(curr->body); }
@@ -19,6 +19,10 @@ struct Finder : PostWalker<Finder> {
     if (expr == nullptr) {
       return;
     }
+    if (tryDepth > 0) {
+      // We are in a try block, so we cannot optimize tail calls.
+      return;
+    }
     if (auto* call = expr->dynCast<Call>()) {
       if (!call->isReturn && call->type == getFunction()->getResults()) {
         tailCalls.push_back(call);