Each shader resource plan is compiled once to a DynamicMethod that evaluates
its resource table graph with plan-local value slots instead of the
interpreter's hashed cache. ASTRO's PLAYROOM goes from about 20 to 60 fps.
Compilation runs on a low-priority "SRT compiler" thread; until a plan is
ready, the interpreter evaluates it, so a new shader no longer stalls the
render thread while its plan is JIT-compiled. A plan whose compilation fails
stays on the interpreter. SHARPEMU_SRT_NATIVE=0 turns the compiled path off;
it is also off when the runtime does not support dynamic code.