Platform-specific behavior and regression testing #179
Description
When compiling to C, we need to choose how to address various integers of different sizes. For example, platforms differ on how to spell a 64-bit int (long vs long long). The finch C output should probably only used fixed-size integer types, rather than size_t types. Additionally, we may want to be careful about how we compile np.int_, ctypes.int_t, etc that may have differing sizes. This came up in #171.
In cases where platform-dependent output is unavoidable, it would be great to have a way to compile to different platforms (setting the integer types appropriately for those platforms). However, I'm not sure if this is possible. It would be best if we could set up our regression tests so that we run with both np.int32 and np.int64, and then run a regression against np.int_ with the appropriate 32 or 64-bit output depending on the current platform.