cpu: Make the indirect predictor into a SimObject

Change-Id: Ice6549773def7d3e944fae450d4a079bc351e2ba
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/15319
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

cpu: Fixed the indirect branch predictor GHR handling

The internal indirect predictor global history was not being updated
properly, resulting in higher than expected miss rates

Also added a parameter to set the size of the indirect predictor GHR

Change-Id: Ibc797816974cba6719da65122801e8919559a003
Signed-off-by: Pau Cabre <pau.cabre@metempsy.com>
Reported-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/16928
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Andrea Mondelli <Andrea.Mondelli@ucf.edu>
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: Add an indirect branch target predictor

This patch adds a configurable indirect branch predictor that can be indexed
by a combination of GHR and path history hashes. Implements the functionality
described in:

"Target prediction for indirect jumps" by Chang, Hao, and Patt
http://dl.acm.org/citation.cfm?id=264209

This is a re-spin of fb9d142 after the revert (bd1c6789).

cpu: Add an indirect branch target predictor

This patch adds a configurable indirect branch predictor that can be indexed
by a combination of GHR and path history hashes. Implements the functionality
described in:

"Target prediction for indirect jumps" by Chang, Hao, and Patt
http://dl.acm.org/citation.cfm?id=264209