Verification using SPIKE

[monisj]

Right now the regression test verification is done via the Linux GCC which is fine but it uses x86 compilers to do which defeats the entire process of verifying riscV core.
While the output is the same spike is based on the SweRV core and is verified plus we have tested its output as well so might be best to integrate its functionality on Burq
But this task has to be multi-theaded as the IDE will grind to a hault
Do note that these compilers either GCC or riscv GCC are single threaded