Intel Architectural LBR Support Going Into Linux 5.9

Intel CPUs have long supported LBR for last branch records as a means of recording the branches to which software has taken along with exposing other control flow information. This has relied upon model-specific registers while with future Intel CPUs this is being folded into a more universal CPU architectural feature. Support for Intel "Arch LBR" is set to come later this year with the Linux 5.9 kernel...