Jit64: Don't store immediate values in register cache

They're now stored in ConstantPropagation instead.

I've also removed the LocationType enum. The location of each guest
register is now tracked using three booleans: Whether it is in ppcState,
whether it is in a host register, and whether it is a known immediate.
The first two of these booleans are stored in the register cache, and
the last one is stored in ConstantPropagation. This new model allows us
to handle the combination of a value simultaneously being in a host
register and being a known immediate. It also keeps track of which
registers are dirty, which was previously kept track of in X64CachedReg.

The old model maps to the new model as follows:

                                default    host_reg    immediate

Default                         true       false       false
Discarded                       false      false       false
Bound                           (!dirty)   true        false
Immediate                       false      false       true
SpeculativeImmediate            true       false       true
[previously unrepresentable]    (!dirty)   true        true

0 files changed, 0 insertions, 0 deletions