Support for bigger whole numbers (long long)

[Catishere]

i'd love to have math operations that operate with big integers.

[Blake-Madden]

In case this helps, with the c++ version at:

https://github.com/Blake-Madden/tinyexpr-plusplus

if you compile with TE_LONG_DOUBLE, that will tell the parser to use long double internally. This will hold either 53-bit (MSVC) or 64-bit (GCC, Clang) integer values.