Replace ErrorHandler with Errors and FormatErrors*

`ErrorHandler` complicated all error handling in wabt, since it was
callback-based. Callbacks would be useful if we ever wanted to change
behavior when an error occurred, but instead all that the handler ever
did was write the errors to stdout/stderr or to a buffer.

This change adds a new class `Error`, which contains an `ErrorLevel`, a
`Location` and an error message. It also replaces ErrorHandler with
`Errors` (a typedef for `std::vector<Error>`), and adds a couple of
functions that can format a list of `Errors` for output:
`FormatErrorsTo{String,File}`.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/binary-reader-logging.cc b/src/binary-reader-logging.cc
index 8010aac5..7edebdd1 100644
--- a/src/binary-reader-logging.cc
+++ b/src/binary-reader-logging.cc
@@ -99,8 +99,8 @@ void BinaryReaderLogging::LogTypes(TypeVector& types) {
   LogTypes(types.size(), types.data());
 }
 
-bool BinaryReaderLogging::OnError(ErrorLevel error_level, const char* message) {
-  return reader_->OnError(error_level, message);
+bool BinaryReaderLogging::OnError(const Error& error) {
+  return reader_->OnError(error);
 }
 
 void BinaryReaderLogging::OnSetState(const State* s) {