[wasm] flag for asm-wasm investigations

src/wasm/module-decoder.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/wasm/module-decoder.h"
 
 #include "src/base/functional.h"
 #include "src/base/platform/platform.h"
 #include "src/flags.h"
 #include "src/macro-assembler.h"
@@ skipping 160 matching lines @@
       }
     }
   }
 };
 
 // The main logic for decoding the bytes of a module.
 class ModuleDecoder : public Decoder {
  public:
   ModuleDecoder(Zone* zone, const byte* module_start, const byte* module_end,
                 ModuleOrigin origin)
-      : Decoder(module_start, module_end), module_zone(zone), origin_(origin) {
+      : Decoder(module_start, module_end),
+        module_zone(zone),
+        origin_(FLAG_assume_asmjs_origin ? kAsmJsOrigin : origin) {
     result_.start = start_;
     if (end_ < start_) {
       error(start_, "end is less than start");
       end_ = start_;
     }
   }
 
   virtual void onFirstError() {
     pc_ = end_;  // On error, terminate section decoding loop.
   }
@@ skipping 1102 matching lines @@
     result.push_back({section_start, name_offset, name_length, payload_offset,
                       payload_length, section_length});
   }
 
   return result;
 }
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8