Minor tweaks for the shader compiler. Also increases the number of base interpreter pipeline variants generated during seeding step for AMD cards. AMD drivers can take upwards of 10 seconds to compile a single interpreter variant which is ridiculous. It's not even stutter at that point, just straight up games freezing if the interpreter required is missing from the cache.
As a workaround, we just add most common options to the base tree, bringing up the variants to ~6600 on AMD while NV keeps a more modest 1100 pipelines. Of course once this set is built the first time, the driver will cache it, so the next bootup is practically instantaneous.

The solution is not perfect, but I feel this closes https://github.com/RPCS3/rpcs3/issues/19085
I was able to remove the driver cache and load up some AAA games. While there was still the odd hang here and there, it wasn't unbearable.