Add tool to test DSP instructions

This should make it easier to test DSP instruction behaviour.

Can be ran like this with debug bios:

A56=/home/user/a56/a56 XBOX=localhost:8731 ./dsp_instruction_test.py dsp_instruction_tests/*-test.json

(Requires a56; example was with -redir tcp:8731::731 in XQEMU CLI)

For test syntax, check the examples. Further changes to input / output syntax are likely.

Most critical missing features / known issues:

Memory can not be set as input / output, no fatal error is generated
Some registers are blacklisted / ignored, no fatal error is generated
DSP assembler errors are silently ignored, no fatal error is generated
JSON and assembly parser issues are not reported properly
Output folder is same as input folder, so it's hard to generate 2 outputs for different machines
No tool to compare JSON output files
Code is ugly

JayFoxRox / xbox-tools