fix BINARYEN_PASS_DEBUG=2, we must not infinitely recurse the pass printer pass while debugging

Author: kripken

src/pass.h

@@ -238,8 +238,9 @@ class Printer : public Pass {
   std::ostream& o;
 
 public:
-  Printer() : o(std::cout) {}
-  Printer(std::ostream* o) : o(*o) {}
+  Printer(std::ostream* o = nullptr) : o(o ? *o : std::cout) {
+    name = "printer";
+  }
 
   void run(PassRunner* runner, Module* module) override;
 };

src/passes/pass.cpp

@@ -150,7 +150,7 @@ void PassRunner::run() {
     for (auto* pass : passes) {
       // ignoring the time, save a printout of the module before, in case this pass breaks it, so we can print the before and after
       std::stringstream moduleBefore;
-      if (passDebug >= 2) {
+      if (passDebug >= 2 && pass->name != "printer") { // the printer pass should not infinitely recurse
         WasmPrinter::printModule(wasm, moduleBefore);
       }
       // prepare to run