[3.14] gh-128605: Add branch protections for x86_64 in asm_trampoline.S (GH-128606) (GH-135077)
Apply Intel Control-flow Technology for x86-64 on asm_trampoline.S.
Required for mitigation against return-oriented programming (ROP)
and Call or Jump Oriented Programming (COP/JOP) attacks.
Manual application is required for the assembly files.
See also: https://sourceware.org/annobin/annobin.html/Test-cf-protection.html
(cherry picked from commit 899cca6dbf)
Co-authored-by: stratakis <cstratak@redhat.com>