// Preprocess the input file in parallel with raw lexing the main file. Ignore
// all tokens that are preprocessed from a file other than the main file (e.g.
- // a header). If we see tokens that are in the preprocessed file bug not the
+ // a header). If we see tokens that are in the preprocessed file but not the
// lexed file, we have a macro expansion. If we see tokens in the lexed file
// that aren't in the preprocessed view, we have macros that expand to no
// tokens, or macro arguments etc.