systemc: Add a missing "const" on one of the sc_event operators.

Change-Id: I073ccb0f2c6d1bfebadb95869d6acf7f4ce565af
Reviewed-on: https://gem5-review.googlesource.com/c/14135
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Get rid of leftovers from unimplemented warnings past.

These warnings were removed when the functionality they warned about
was implemented, but there were some leftovers like unnecessary
includes and some helper functions which hid gem5 specific headers
from the ext directory.

Change-Id: Ic886ac0f1264687524e3a7b7eaab8836f318a5a2
Reviewed-on: https://gem5-review.googlesource.com/c/13398
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Distinguish internal events from normal sc_events.

The internal events aren't supposed to show up in the namespace or as
children of objects.

Change-Id: Id04b9bfe2e1f8f216390dd989797558eaf33d715
Reviewed-on: https://gem5-review.googlesource.com/c/13309
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Add an error check to the deprecated notify_delayed.

This can't override pending notifications like normal notify does.

Change-Id: Ie5f12a97ffdcc3dfca20fa7852f89687ee8bfca3
Reviewed-on: https://gem5-review.googlesource.com/c/13305
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Make sure otherwise unnamed events get autogenerated ones.

Change-Id: Iec4e0bd504e70d0096a4c90d5fbba9565dd0deed
Reviewed-on: https://gem5-review.googlesource.com/c/13205
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Get rid of the unused warning function in sc_event_finder_t.

Change-Id: Id615856af7ea366e499747e00f66924a25623663
Reviewed-on: https://gem5-review.googlesource.com/12261
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Implement much of events, event lists and event exprs.

Three things aren't yet implemented, waking up processes which are
sensitive to the event, triggering of events, and garbage collecting
list objects which came from expression objects.

The garbage collection aspect is problematic since there doesn't seem
to be a correct way to implement it given the constraints in the spec,
including the way that's implemented by Accellera. It's something that
will need to be dealt with at some point, but in the interest of
forward progress it's being ignored for now.

Change-Id: Ic4e3c219ff482729f1f1302ab10181a798d48041
Reviewed-on: https://gem5-review.googlesource.com/11711
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Add deprecated notify_delayed functions.

Change-Id: I8ec68920b35f9207b6856a0b1ddfdf7545b7148a
Reviewed-on: https://gem5-review.googlesource.com/11269
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Add the nonstandard triggered function sc_event.

The Accellera implementation of sc_event has a non-standard triggered
function which returns whether or not that particular event has been
triggered in the current delta cycle. The tests call it, so we probably
need to have it.

Change-Id: I675099b65d00e09536618d4d2d707bf3c25e3bde
Reviewed-on: https://gem5-review.googlesource.com/11187
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

systemc: Seperate the "external" header interface.

Most (but not all) of the SystemC headers are part of the "external"
interface that an existing, standard compliant module would include
through <systemc.h> or <systemc>. Since those follow slightly different
rules (relative includes, no gem5 includes), this change separates them
out so that they're easier to identify.

Also, this change moves the other files into a "core" subdirectory,
with the intention to add a "dt", aka data type, directory some time in
the future when those standard defined types are implemented.

Change-Id: Ida63f9cc0bc0431024d4dd691cc5b22b944a99a8
Reviewed-on: https://gem5-review.googlesource.com/10835
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>