VS warning fixes.

Change-Id: I19662241d56560c064cff73dbebfb2a81d226934

src/idl_gen_cpp.cpp

@@ -478,6 +478,7 @@ class CppGenerator : public BaseGenerator {
           : ev.name;
     } else {
       assert(false);
+      return ev.name;
     }
   }
 

src/idl_gen_text.cpp

@@ -49,7 +49,7 @@ void OutputIdentifier(const std::string &name, const IDLOptions &opts,
 // for a single FlatBuffer value into JSON format.
 // The general case for scalars:
 template<typename T> bool Print(T val, Type type, int /*indent*/,
-                                Type */*union_type*/,
+                                Type * /*union_type*/,
                                 const IDLOptions &opts,
                                 std::string *_text) {
   std::string &text = *_text;