The class CodeBuffer typedefs csize_t as int. However, since this type represents code size, this really should be an unsigned type. As the comment next to the typedef states "code size type; would be size_t except for history", but we do not want it to be size_t since a 32-bit size is large enough for a code buffer and size_t would unnecessarily increase the memory footprint.
Some newer uses of csize_t have negative values. These types need to be changed to an appropriate type like ptrdiff_t or int.