microsoft/spirv_to_dxil: Fix spirv2dxil I/O to use binary mode

The spirv2dxil binary currently incorrectly reads its input and writes its output in text mode. This causes it to both not read SPIR-V input past the first NUL character and erroneously add carriage returns (\r) before every 0x0A byte (i.e. line feed \n), resulting in misread SPIR-V and invalid DXIL output.