Change {Source,Binary}ErrorHandler to C++ (#403)

Added some new classes:

* BinaryErrorHandler: abstract base class
* BinaryErrorHandlerFile: writes errors to a FILE*
* SourceErrorHandler: abstract base class
* SourceErrorHandlerNop: eats all errors
* SourceErrorHandlerFile: writes errors to a FILE*

There are some specific ones as well:

* BinaryErrorHandlerAssert: used in wasm-interp to handle writing out a
  custom header with assertion "failures"; i.e. places where the error
  handler should fire.
* BinaryErrorHandlerModule: used when parsing a .wast, but there's an
  embedded binary file.

1 files changed, 3 insertions, 2 deletions

diff --git a/src/binary-reader-ast.h b/src/binary-reader-ast.h
index 07599033..49d99d2e 100644
--- a/src/binary-reader-ast.h
+++ b/src/binary-reader-ast.h
@@ -23,12 +23,13 @@ namespace wabt {
 
 struct Module;
 struct ReadBinaryOptions;
+class BinaryErrorHandler;
 
 Result read_binary_ast(const void* data,
                        size_t size,
-                       const struct ReadBinaryOptions* options,
+                       const ReadBinaryOptions* options,
                        BinaryErrorHandler*,
-                       struct Module* out_module);
+                       Module* out_module);
 
 } // namespace wabt