Merge remote-tracking branch 'remotes/rth-gitlab/tags/pull-tcg-20210501' into staging

Include cleanups.
Decodetree enhancements for power10.

# gpg: Signature made Sat 01 May 2021 19:50:22 BST
# gpg:                using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg:                issuer "richard.henderson@linaro.org"
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [full]
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A  05C0 64DF 38E8 AF7E 215F

* remotes/rth-gitlab/tags/pull-tcg-20210501:
  decodetree: Extend argument set syntax to allow types
  decodetree: Add support for 64-bit instructions
  decodetree: More use of f-strings
  decodetree: Introduce whex and whexC helpers
  exec: Remove accel/tcg/ from include paths

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>