Merge remote-tracking branch 'remotes/quic/tags/pull-hex-20211103' into staging

Merge remote-tracking branch 'remotes/quic/tags/pull-hex-20211103' into staging

This series adds support for the Hexagon Vector eXtensions (HVX)

These instructions are documented here
https://developer.qualcomm.com/downloads/qualcomm-hexagon-v66-hvx-programmer-s-reference-manual

Hexagon HVX is a wide vector engine with 128 byte vectors.

See patch 01 Hexagon HVX README for more information.

*** Changes in v2 ***
Remove HVX tests from makefile to avoid need for toolchain upgrade

# gpg: Signature made Wed 03 Nov 2021 05:14:44 PM EDT
# gpg:                using RSA key 7B0244FB12DE4422
# gpg: Good signature from "Taylor Simpson (Rock on) <tsimpson@quicinc.com>" [marginal]
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 3635 C788 CE62 B91F D4C5  9AB4 7B02 44FB 12DE 4422

* remotes/quic/tags/pull-hex-20211103: (30 commits)
  Hexagon HVX (tests/tcg/hexagon) histogram test
  Hexagon HVX (tests/tcg/hexagon) scatter_gather test
  Hexagon HVX (tests/tcg/hexagon) hvx_misc test
  Hexagon HVX (tests/tcg/hexagon) vector_add_int test
  Hexagon HVX (target/hexagon) import instruction encodings
  Hexagon HVX (target/hexagon) instruction decoding
  Hexagon HVX (target/hexagon) import semantics
  Hexagon HVX (target/hexagon) helper overrides - vector stores
  Hexagon HVX (target/hexagon) helper overrides - vector loads
  Hexagon HVX (target/hexagon) helper overrides - vector splat and abs
  Hexagon HVX (target/hexagon) helper overrides - vector compares
  Hexagon HVX (target/hexagon) helper overrides - vector logical ops
  Hexagon HVX (target/hexagon) helper overrides - vector max/min
  Hexagon HVX (target/hexagon) helper overrides - vector shifts
  Hexagon HVX (target/hexagon) helper overrides - vector add & sub
  Hexagon HVX (target/hexagon) helper overrides - vector assign & cmov
  Hexagon HVX (target/hexagon) helper overrides for histogram instructions
  Hexagon HVX (target/hexagon) helper overrides infrastructure
  Hexagon HVX (target/hexagon) TCG generation
  Hexagon HVX (target/hexagon) helper functions
  ...

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>