Branch predictor cleanup. Chapter 10 now matches the hardware

Created by: rosethompson

• Renamed signals to match figure 10.18.
• Renamed signals to match new figures.
• More signal renames.
• gshare cleanup.
• PHT was enabled using the wrong ~flush and ~stall.
• Create module for instruction class prediction and decoding.
• Branch predictor cleanup.
• Signal name changes.
• Modified the BTB to save power by not updating when the prediction is unchanged.
• This icpred and btb changes are causing a performance issue.
• Undid the btb update as it reduces performance.
• Name changes to reflect diagrams.
• Found the performance bug with the branch predictor btb power saving update.
• Name cleanup.
• Minor fix to btb.
• More btb cleanup.
• Branch predictor cleanup. I think Ch 10 is now done except for BTB performance analysis and the section on running benchmarks and collecting data.
• Set bp to use instruction class prediction by default.