Pull READ_IMPLIES_EXEC changes from Borislav Petkov:
 "Split the old READ_IMPLIES_EXEC workaround from executable
  PT_GNU_STACK now that toolchains long support PT_GNU_STACK marking and
  there's no need anymore to force modern programs into having all its
  user mappings executable instead of only the stack and the PROT_EXEC
  ones.

  Disable that automatic READ_IMPLIES_EXEC forcing on x86-64 and
  arm64.

  Add tables documenting how READ_IMPLIES_EXEC is handled on x86-64, arm
  and arm64.

  By Kees Cook"

* tag 'core_core_updates_for_5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arm64/elf: Disable automatic READ_IMPLIES_EXEC for 64-bit address spaces
  arm32/64/elf: Split READ_IMPLIES_EXEC from executable PT_GNU_STACK
  arm32/64/elf: Add tables to document READ_IMPLIES_EXEC
  x86/elf: Disable automatic READ_IMPLIES_EXEC on 64-bit
  x86/elf: Split READ_IMPLIES_EXEC from executable PT_GNU_STACK
  x86/elf: Add table to document READ_IMPLIES_EXEC