Read JSON with options: Allow INF and NAN flag fails to read positive infinity values

[dcascais]

Description
When enabling the YYJSON_READ_ALLOW_INF_AND_NAN flag, the JSON read fails, returning an unexpected character error with code 6.

• This happens with both array and object values.
• This doesn't happen with negative infinity as those values are caught by the char_is_number(*cur) check, and handled accordingly.
• Possible fix below.

Additional context

Running the code below results in these two errors:

• Array JSON read error: unexpected character. Code: 6, at position: 28
• Object JSON read error: unexpected character. Code: 6, at position: 78

How to reproduce

yyjson_read_flag flg = YYJSON_READ_ALLOW_INF_AND_NAN;

//
// Read array with nan and inf values
//
char arr_str[] = "[1, 123e999, nan, NaN, NAN, inf, infinity, Infinity, INF, -inf, -infinity, -Infinity, -INF]";
size_t arr_str_len = strlen(arr_str);
yyjson_read_err arr_err;

yyjson_doc *arr_doc = yyjson_read_opts(arr_str, arr_str_len, flg, NULL, &arr_err);
if (!arr_doc) {
    fprintf(stderr, "Array JSON read error: %s. Code: %u, at position: %ld\n", arr_err.msg, arr_err.code, arr_err.pos);
}
yyjson_doc_free(arr_doc);

//
// Read object with nan and inf values
//
char obj_str[] = "{\"small\": 1, \"large\": 123e999, \"nan1\": nan, \"nan2\": NaN, \"nan3\": NAN, \"inf1\": inf, \"inf2\": infinity, \"inf3\": Infinity, \"inf4\": INF, \"inf5\": -inf, \"inf6\": -infinity, \"inf7\": -Infinity, \"inf8\": -INF}";
size_t obj_str_len = strlen(obj_str);
yyjson_read_err obj_err;

yyjson_doc *obj_doc = yyjson_read_opts(obj_str, obj_str_len, flg, NULL, &obj_err);
if (!obj_doc) {
    fprintf(stderr, "Object JSON read error: %s. Code: %u, at position: %ld\n", obj_err.msg, obj_err.code, obj_err.pos);
}
yyjson_doc_free(obj_doc);

Possible fix
Replace all instances of:
if (has_flag(ALLOW_INF_AND_NAN) && *cur == 'N')
with:
if (has_flag(ALLOW_INF_AND_NAN) && *cur == 'i' || *cur == 'I' || *cur == 'N')

[ibireme]

Thanks, fixed: 84c683a