NT_GNU_PROPERTY_TYPE_0 in a .note.gnu.property section "contains a
program property note which describes special handling requirements
for linker and run-time loader." (from the System V Application Binary
Interface - Linux Extensions")
Intel CET uses two processor-specific program properties in
NT_GNU_PROPERTY_TYPE_0: GNU_PROPERTY_X86_FEATURE_1_IBT to indicate that
all executable sections are compatible with Indirect Branch Tracking,
and GNU_PROPERTY_X86_FEATURE_1_SHSTK to indicate that sections are
compatible with shadow stack.
A later change should add decoding of the individual properties.
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
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