Fix a typo, unkown -> unknown
Handle -dumpversion in the same way as --version

This is called when wrapping gas-preprocessor around a normal
linux gcc.
Support running the preprocessor only, for deps
Add a script for comparing the disasm of all asm files
Don't convert add to add.w when using gas
Don't remove dots for .Llocal symbols when using gas
Don't do literal restructuring when using gas