A new generated code alone is 4000 lines long [1]. The actual code added is just 2000 lines, and some are used to pay debts, I mean, to make a proper code generator. It is debatable whether that generator should count in the number of lines, since you can always write a generator in a simpler scripting language (for example, Rust uses Python to generate the `unicode-xid` crate). In any case however it is far less complex and, in my opinion, much smaller than the entire C parser proper.

[1] https://github.com/dlang/dmd/pull/15307/files#diff-3677bcc89...