Passing memory endness info from SimState to SimMemory

[YHZX2013]

The default endness of SimMemory is "Iend_BE", it won't pass the arch endness info to SimMemory in original code.

[rhelmot]

The default endness being big-endian regardless of architecture is intentional, and there is a lot of code which relies on this behavior. state.memory is meant to be a really basic memory access interface designed for loading chunks of bytes, not structured information like endian-swapped words. If you want to extract integer data and expect endians to work by default, you should use state.mem instead. Take a look at https://docs.angr.io/docs/structured_data.html