Branch predictor acuracy fixes caused by last two weeks optimazations"

Created by: rosethompson

• Experimental branch prediction optimization.
• More simplifications to the BP.
• Removed another bit from btb class.
• Partial fix for gshare bugs from the last two weeks.
• Hacked commit. Fixes the gshare bugs introduced last week. Need to recover the good changes in the next commit.
• Partial improvement.
• Further branch predictor improvements.
• Created copy of gshare. I think there may be a simpler implementation.
• Fixed bug in basic gshare implementation. Should be a better comparison to the speculative versions now.
• Updated global history predictor.
• Fixed global history predictor.
• More fixeds to global history.
• Updated gshare (no speculation) to have better performance.