Parse and compile Intel 8080 sources

Implement a new cpu parser and code generator for Intel 8080 mnemonics (which is binary compatible with Z80). New command line parameter -m8080. New "CPU" directive: CPU 8080

Add reference source in asmtests folder (copy z80 as template and reduce accordingly)

Mapping between Intel 8080 and Z80 mnemonics are listed here: https://retroprogramming.it/2021/02/8080-z80-instruction-set/

All info about chip: https://en.wikipedia.org/wiki/Intel_8080