BR 812417: Deadman counter for macro expansion
BR 812417: Deadman counter for macro expansion

Per BR 812417, certain macro expansions can hang NASM.  Allow a
deadman counter (currently set to 2^20) to fail out if it gets
ridiculous.

projedi/nasm,letolabs/nasm,Distrotech/nasm,turingstudio/nasm,projedi/nasm,techkey/nasm,turingstudio/nasm,techkey/nasm,letolabs/nasm,letolabs/nasm,Distrotech/nasm,techkey/nasm,turingstudio/nasm,projedi/nasm,projedi/nasm,Distrotech/nasm,projedi/nasm,turingstudio/nasm,techkey/nasm,techkey/nasm,Distrotech/nasm