The actual Spike package consists of a whole bunch of libraries. This
installs a pkg-config file for each generated library, and a meta
pkg-config file (riscv-spike.pc) that links in all the other Spike
libraries except dummy_rocc (which I figure isn't interesting).
This allows me to package and install spike, and then use that package
to build an extension library (so I don't have to fork Spike for my
own ISA extension).
Moved cross-compiler to /xcc/ rather than /
Added ISA sim in /sim/
Added Proxy Kernel in /pk/ (to be cleaned up)
Added opcode map to /opcodes/ (ditto)
Added documentation to /doc/