[v5,00/19] Handle variable XSAVE layouts

  Changes since V4:

- Added a new target method to fetch the XSAVE layout rather than
  using an internal TARGET_OBJECT_X86_XSAVE_LAYOUT.  Patch 1 from V4
  is now split into two patches: one to add the new structure, the
  second adds the new target method and stores it in the tdep.

- Patch 6 is a quick fixup for x86-fbsd-nat.h

- Patches 7 and 8 are new and fix an issue Simon Marchi noticed where
  FreeBSD and Linux native architectures can run into errors due to
  using ptrace in the target read_description method if the current
  inferior has no live process.  The general rule there is to just use
  a default tdesc for the architecture if inferior_ptid is null.  I've
  only compiled/tested this on Linux and FreeBSD x86-64.

- Patches 15 and 17 for gdbserver have been largely reworked to make
  use of C inheritance to remove the need for changes to the FXSAVE
  portion of the XSAVE area.

- Patches 16 and 19 are new fixes for bugs I noticed specific to
  AVX-512 handling in gdbserver.

Aleksandar Paunovic (2):
  gdbserver: Refactor the legacy region within the xsave struct
  gdbserver: Use x86_xstate_layout to parse the XSAVE extended state
    area.

John Baldwin (17):
  x86: Add an x86_xsave_layout structure to handle variable XSAVE
    layouts.
  gdb: Store an x86_xsave_layout in i386_gdbarch_tdep.
  core: Support fetching x86 XSAVE layout from architectures.
  nat/x86-cpuid.h: Add x86_cpuid_count wrapper around __get_cpuid_count.
  x86 nat: Add helper functions to save the XSAVE layout for the host.
  x86-fbsd-nat: Add missing public label.
  *-fbsd-nat: Handle null inferior in read_description.
  *-linux-nat: Handle null inferior in read_description.
  gdb: Update x86 FreeBSD architectures to support XSAVE layouts.
  gdb: Support XSAVE layouts for the current host in the FreeBSD x86
    targets.
  gdb: Update x86 Linux architectures to support XSAVE layouts.
  gdb: Support XSAVE layouts for the current host in the Linux x86
    targets.
  gdb: Use x86_xstate_layout to parse the XSAVE extended state area.
  gdbserver: Add a function to set the XSAVE mask and size.
  gdbserver: Clear upper ZMM registers in the right location.
  x86: Remove X86_XSTATE_SIZE and related constants.
  gdbserver: Simplify handling of ZMM registers.

 gdb/aarch64-fbsd-nat.c     |   3 +
 gdb/aarch64-linux-nat.c    |   3 +
 gdb/amd64-fbsd-nat.c       |  43 +--
 gdb/amd64-fbsd-tdep.c      |  12 +-
 gdb/amd64-linux-nat.c      |   6 +-
 gdb/amd64-linux-tdep.c     |  11 +-
 gdb/arm-fbsd-nat.c         |   3 +
 gdb/arm-linux-nat.c        |   3 +
 gdb/configure.nat          |   8 +-
 gdb/corelow.c              |  21 ++
 gdb/gdbarch-gen.h          |   9 +
 gdb/gdbarch.c              |  32 +++
 gdb/gdbarch.h              |   1 +
 gdb/gdbarch_components.py  |  11 +
 gdb/i386-fbsd-nat.c        |  42 +--
 gdb/i386-fbsd-tdep.c       |  72 ++---
 gdb/i386-fbsd-tdep.h       |  10 +-
 gdb/i386-linux-nat.c       |   8 +-
 gdb/i386-linux-tdep.c      |  67 ++---
 gdb/i386-linux-tdep.h      |  21 +-
 gdb/i386-tdep.c            |  19 +-
 gdb/i386-tdep.h            |   4 +
 gdb/i387-tdep.c            | 522 +++++++++++++++++++++++--------------
 gdb/i387-tdep.h            |   9 +
 gdb/mips-linux-nat.c       |   3 +
 gdb/nat/x86-cpuid.h        |  32 +++
 gdb/nat/x86-xstate.c       |  67 +++++
 gdb/nat/x86-xstate.h       |  35 +++
 gdb/ppc-linux-nat.c        |   3 +
 gdb/riscv-linux-nat.c      |   3 +
 gdb/s390-linux-nat.c       |   3 +
 gdb/target-debug.h         |  20 ++
 gdb/target-delegates.c     |  27 ++
 gdb/target.c               |   6 +
 gdb/target.h               |   7 +
 gdb/x86-fbsd-nat.c         |  21 ++
 gdb/x86-fbsd-nat.h         |  20 ++
 gdb/x86-linux-nat.c        |   6 +
 gdb/x86-linux-nat.h        |   7 +
 gdbserver/configure.srv    |  12 +-
 gdbserver/i387-fp.cc       | 268 +++++++++----------
 gdbserver/i387-fp.h        |   4 +-
 gdbserver/linux-x86-low.cc |  10 +-
 gdbsupport/x86-xstate.h    |  70 +++--
 44 files changed, 1049 insertions(+), 515 deletions(-)
 create mode 100644 gdb/nat/x86-xstate.c
 create mode 100644 gdb/nat/x86-xstate.h