Merge remote-tracking branch 'remotes/rth-gitlab/tags/pull-x86-20210519' into staging

Merge remote-tracking branch 'remotes/rth-gitlab/tags/pull-x86-20210519' into staging

Eliminate user-only helper stubs for privledged insns.

# gpg: Signature made Wed 19 May 2021 19:24:27 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-x86-20210519: (50 commits)
  target/i386: Remove user-only i/o stubs
  target/i386: Move helper_check_io to sysemu
  target/i386: Create helper_check_io
  target/i386: Pass in port to gen_check_io
  target/i386: Tidy gen_check_io
  target/i386: Exit tb after wrmsr
  target/i386: Eliminate user stubs for read/write_crN, rd/wrmsr
  target/i386: Inline user cpu_svm_check_intercept_param
  target/i386: Unify invlpg, invlpga
  target/i386: Move invlpg, hlt, monitor, mwait to sysemu
  target/i386: Pass env to do_pause and do_hlt
  target/i386: Cleanup read_crN, write_crN, lmsw
  target/i386: Remove user stub for cpu_vmexit
  target/i386: Remove pc_start argument to gen_svm_check_intercept
  target/i386: Tidy svm_check_intercept from tcg
  target/i386: Simplify gen_debug usage
  target/i386: Mark some helpers as noreturn
  target/i386: Eliminate SVM helpers for user-only
  target/i386: Implement skinit in translate.c
  target/i386: Assert !GUEST for user-only
  ...

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