Move the JIT registration logic in its own file

Move the JITed function/basic-block registration logic out of the CPU
subsystem in order to add JIT registration to JITed DSP and
Video/VertexLoader code.

This necessary in order to add /tmp/perf-$pid.map support to other
JITed code as they need to write to the same file.
VertexLoader: register with JIT Register

Allows profiling/debugging tools to know about JITed VertexLoader
code.
JitAsmCommon: register with JIT Register

Allows profiling/debugging tools to know about JITed code.