cpu: Added 8KB and 64KB TAGE-SC-L branch predictor

The original paper of the branch predictor can be found here:
http://www.jilp.org/cbp2016/paper/AndreSeznecLimited.pdf

Change-Id: I684863752407685adaacedebb699205c3559c528
Reviewed-on: https://gem5-review.googlesource.com/c/14855
Reviewed-by: Sudhanshu Jha <sudhanshu.jha@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

cpu: Proposal for changing the indirect branch predictor interface

Now the indirect branch predictor handles its own GHR instead of getting
the one from the direction predictor.

Also, now the commit method of the indirect predictor is called for every
pending branch on an update, as the indirect predictors may want to update
their interal structures/histories with the information of each branch.

Change-Id: I7053fbea42a53960a3bc1ba32912cc99c160511e
Reviewed-on: https://gem5-review.googlesource.com/c/15318
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

cpu: Made TAGE a SimObject that can be used by other predictors

The TAGE implementation is now a SimObject so that other branch predictors
can easily use it. It has also been updated with the latest available TAGE
implementation from Andre Seznec:

http://www.irisa.fr/alf/downloads/seznec/TAGE-GSC-IMLI.tar

Change-Id: I2251b8b2d7f94124f9955f52b917dc3b064f090e
Reviewed-on: https://gem5-review.googlesource.com/c/15317
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

cpu: Added new stats to TAGE and LTAGE branch predictors

They are basically used to tell wich component of the predictor is
providing the prediction and whether it is correct or wrong

Change-Id: I7b3db66535f159091f1b37d70c2d942d50b20fb2
Signed-off-by: Pau Cabre <pau.cabre@metempsy.com>
Reviewed-on: https://gem5-review.googlesource.com/c/14535
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

cpu: split LTAGE implementation into a base TAGE and a derived LTAGE

The new derived LTAGE is equivalent to the original LTAGE implementation
The default values of the TAGE branch predictor match the settings of the
8C-TAGE configuration described in https://www.jilp.org/vol8/v8paper1.pdf

Change-Id: I8323adbfd5c9a45db23cfff234218280e639f9ed
Signed-off-by: Pau Cabre <pau.cabre@metempsy.com>
Reviewed-on: https://gem5-review.googlesource.com/c/14435
Reviewed-by: Sudhanshu Jha <sudhanshu.jha@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>