Description
Related to #10238
Some people find the argument overwrite_x to be confusing (cupy/cupy#1988). The argument allows the implementation to use the input array as scratch space which may or may not have the output written to it. However, some users interpret it as an inplace transform where the output is written back to the input array.
It has been suggested to remove it entirely but could also be renamed. FFTW calls this FFTW_DESTROY_INPUT which makes it clearer that this is not a guarunteed inplace transform/out-parameter.