llvm

eba2fde4 - Reland: [LFI][X86] Add X86 LFI target and system instruction rewrites (#207892)

Reland: [LFI][X86] Add X86 LFI target and system instruction rewrites (#207892) Reintroduction of #189569 using the MCRegisterClass accessor API, which was recently modified and caused a build error when the previous PR was merged since it was not rebased onto the latest commit.