bdiff: check and cast first parameter value on putbe32() calls Eliminates mercurial/bdiff.c(383) : warning C4244: 'function' : conversion from '__int64' to 'uint32_t', possible loss of data mercurial/bdiff.c(384) : warning C4244: 'function' : conversion from '__int64' to 'uint32_t', possible loss of data mercurial/bdiff.c(385) : warning C4244: 'function' : conversion from 'Py_ssize_t' to 'uint32_t', possible loss of data when compiling for Windows x64 target using the Microsoft compiler.