mem-ruby: Enable set size increase

Add NUMBER_BITS_PER_SET environment variable to control
the size of the bitmask in Set.hh (default=64).
Necessary for configs which require >64 instances of a given
machine type. This can be set in the build_opts file, e.g.
by adding the following line:
NUMBER_BITS_PER_SET = <number>

Change-Id: I314a3cadca8ce975fcf4a60d9022494751688e88
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18968
Reviewed-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem: write combining for ruby protocols

This patch adds support for write-combining in ruby.

ruby: added stl vector of ints to be used by SLICC

ruby: add BoolVec

The BoolVec typedef and insertion operator overload function simplify usage of
vectors of type bool

ruby: set: reimplement using std::bitset
The current Set data structure is slow and therefore is being reimplemented
using std::bitset. A maximum limit of 64 is being set on the number of
controllers of each type. This means that for simulating a system with more
controllers of a given type, one would need to change the value of the variable
NUMBER_BITS_PER_SET

ruby: replace global g_abs_controls with per-RubySystem var

This is another step in the process of removing global variables
from Ruby to enable multiple RubySystem instances in a single simulation.

The list of abstract controllers is per-RubySystem and should be
represented that way, rather than as a global.

Since this is the last remaining Ruby global variable, the
src/mem/ruby/Common/Global.* files are also removed.

Ruby: Remove RubyEventQueue
This patch removes RubyEventQueue. Consumer objects now rely on RubySystem
or themselves for scheduling events.

Ruby: Remove the unused src/mem/ruby/common/Driver.* files.

Scons: Remove Werror=False in SConscript files

This patch removes the overriding of "-Werror" in a handful of
cases. The code compiles with gcc 4.6.3 and clang 3.0 without any
warnings, and thus without any errors. There are no functional changes
introduced by this patch. In the future, rather than ypassing
"-Werror", address the warnings.

BuildEnv: Eliminate RUBY as build environment variable
This patch replaces RUBY with PROTOCOL in all the SConscript files as
the environment variable that decides whether or not certain components
of the simulator are compiled.

ruby: get rid of ruby's Debug.hh

Get rid of the Debug class
Get rid of ASSERT and use assert
Use DPRINTFR for ProtocolTrace

ruby: style pass

ruby: Convert most Ruby objects to M5 SimObjects.
The necessary companion conversion of Ruby objects generated by SLICC
are converted to M5 SimObjects in the following patch, so this patch
alone does not compile.
Conversion of Garnet network models is also handled in a separate
patch; that code is temporarily disabled from compiling to allow
testing of interim code.

ruby: add RUBY sticky option that must be set to add ruby to the build
Default is false

ruby: Migrate all of ruby and slicc to SCons.
Add the PROTOCOL sticky option sets the coherence protocol that slicc
will parse and therefore ruby will use. This whole process was made
difficult by the fact that the set of files that are output by slicc
are not easily known ahead of time. The easiest thing wound up being
to write a parser for slicc that would tell me. Incidentally this
means we now have a slicc grammar written in python.