wasm: add flag to dump modules

src/base/platform/platform.h

Index: src/base/platform/platform.h
diff --git a/src/base/platform/platform.h b/src/base/platform/platform.h
index 89d6225edebbde229917383aae280cb0196d5fc8..4993dc861474339d5c0202d6f76138abf32ae632 100644
--- a/src/base/platform/platform.h
+++ b/src/base/platform/platform.h
@@ -142,6 +142,7 @@ class OS {
   static FILE* FOpen(const char* path, const char* mode);
   static bool Remove(const char* path);
 
+  static char DirectorySeparator();
   static bool isDirectorySeparator(const char ch);
 
   // Opens a temporary file, the file is auto removed on close.