8689f5e6e7
This change introduces subtarget features to predicate certain instructions and system registers that are available only on 'A' profile targets. Those features are not present when targeting a generic CPU, which is the default processor. In other words the generic CPU now means the intersection of 'A' and 'R' profiles. To maintain backwards compatibility we enable the features that correspond to -march=armv8-a when the architecture is not explicitly specified on the command line. References: https://developer.arm.com/documentation/ddi0600/latest Differential Revision: https://reviews.llvm.org/D110065