BLD: parser c-build warnings

[jreback]

These just need some casting I think

andas/_libs/src/parser/tokenizer.c:1091:41: warning: comparison of integers of different signs: 'int64_t' (aka 'long long') and 'unsigned long long' [-Wsign-compare]
                            self->lines == start_lines + line_limit) {
                            ~~~~~~~~~~~ ^  ~~~~~~~~~~~~~~~~~~~~~~~~
pandas/_libs/src/parser/tokenizer.c:1180:15: warning: comparison of integers of different signs: 'size_t' (aka 'unsigned long') and 'int64_t' (aka 'long long') [-Wsign-compare]
    if (nrows > self->lines) {
        ~~~~~ ^ ~~~~~~~~~~~
pandas/_libs/src/parser/tokenizer.c:1196:20: warning: comparison of integers of different signs: 'size_t' (aka 'unsigned long') and 'int64_t' (aka 'long long') [-Wsign-compare]
    if (char_count < self->stream_len) {
        ~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~
pandas/_libs/src/parser/tokenizer.c:1244:17: warning: comparison of integers of different signs: 'size_t' (aka 'unsigned long') and 'int64_t' (aka 'long long') [-Wsign-compare]
    if (new_cap < self->words_cap) {
        ~~~~~~~ ^ ~~~~~~~~~~~~~~~
pandas/_libs/src/parser/tokenizer.c:1268:17: warning: comparison of integers of different signs: 'size_t' (aka 'unsigned long') and 'int64_t' (aka 'long long') [-Wsign-compare]
    if (new_cap < self->stream_cap) {
        ~~~~~~~ ^ ~~~~~~~~~~~~~~~~
pandas/_libs/src/parser/tokenizer.c:1296:17: warning: comparison of integers of different signs: 'size_t' (aka 'unsigned long') and 'int64_t' (aka 'long long') [-Wsign-compare]
    if (new_cap < self->lines_cap) {
        ~~~~~~~ ^ ~~~~~~~~~~~~~~~
pandas/_libs/src/parser/tokenizer.c:1351:47: warning: comparison of integers of different signs: 'long long' and 'size_t' (aka 'unsigned long') [-Wsign-compare]
        if (!all && self->lines - start_lines >= nrows) break;