base: Save and restore the width setting of streams used with cprintf.

The flags, precision, and fill character were all being saved and
restored, but cprintf might also change the width setting of the
stream, and that wasn't being saved or restored and could leak from
the cprintf statement.

This change adds the code to save and restore that value.

Change-Id: Ibedb26f7f538cd3be4fe0462d2ee4e5efd62bc59
Reviewed-on: https://gem5-review.googlesource.com/12571
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

misc: Updates for gcc7.2 for x86

GCC 7.2 is much stricter than previous GCC versions. The following changes
are needed:

* There is now a warning if there is an implicit fallthrough between two
case statments. C++17 adds the [[fallthrough]]; declaration. However,
to support non C++17 standards (i.e., C++11), we use M5_FALLTHROUGH.
M5_FALLTHROUGH checks for [[fallthrough]] compliant C++17 compiler and
if that doesn't exist, it defaults to nothing (no older compilers
generate warnings).
* The above resulted in a couple of bugs that were found. This is noted
in the review request on gerrit.
* throw() for dynamic exception specification is deprecated
* There were a couple of new uninitialized variable warnings
* Can no longer perform bitwise operations on a bool.
* Must now include <functional> for std::function
* Compiler bug for void* lambda. Changed to auto as work around. See
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82878

Change-Id: I5d4c782a4e133fa4cdb119e35d9aff68c6e2958e
Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-on: https://gem5-review.googlesource.com/5802
Reviewed-by: Gabe Black <gabeblack@google.com>

style: [patch 1/22] use /r/3648/ to reorganize includes

base: Fix a few incorrectly handled print format cases

This patch ensures cases like %0.6u, %06f, and %.6u are processed correctly.
The case like %06f is ambiguous and was made to match printf. Also, this patch
removes the goto statement in cprintf.cc in favor of a function call.

Make commenting on close namespace brackets consistent.

Ran all the source files through 'perl -pi' with this script:

s|\s*(};?\s*)?/\*\s*(end\s*)?namespace\s*(\S+)\s*\*/(\s*})?|} // namespace $3|;
s|\s*};?\s*//\s*(end\s*)?namespace\s*(\S+)\s*|} // namespace $2\n|;
s|\s*};?\s*//\s*(\S+)\s*namespace\s*|} // namespace $1\n|;

Also did a little manual editing on some of the arch/*/isa_traits.hh files
and src/SConscript.

cprintf: support a configurable width and precision ("*" in printf)

Get rid of the gross operator,()/variadic macro hack
that made ccprintf and friends work, turn it into a
normal function (though it still has a slightly strange
implementation.) All instances of variadic macros
are not yet removed, but I know how, and it will happen.

One side effect of this new implementation is that a
cprintf statement can now only have 16 parameters, though
it's easy enough to raise this number if needed.

Updated Authors from bk prs info

New directory structure:
- simulator source now in 'src' subdirectory
- imported files from 'ext' repository
- support building in arbitrary places, including
outside of the source tree. See comment at top
of SConstruct file for more details.
Regression tests are temporarily disabled; that
syetem needs more extensive revisions.

SConstruct:
Update for new directory structure.
Modify to support build trees that are not subdirectories
of the source tree. See comment at top of file for
more details.
Regression tests are temporarily disabled.
src/arch/SConscript:
src/arch/isa_parser.py:
src/python/SConscript:
Update for new directory structure.