This relands commits e43924a75145d2f9e722f74b673145c3e62bfd07, a43f36142c501e2d3f4797ef938db4e0c5e0eeec, bf94eac6a3f7c5cd8941956d44c15524fa3751bd with MSan buildbot https://lab.llvm.org/buildbot/#/builders/5/builds/30139 use-of-uninitialized-value errors fixed. Differential Revision: https://reviews.llvm.org/D127812
This reverts commit e43924a75145d2f9e722f74b673145c3e62bfd07. Reason: Patch broke the MSan buildbots. More information is available on the original phabricator review: https://reviews.llvm.org/D127812
This is Function Multi Versioning (FMV) implementation for AArch64 target in accordance with Beta Arm C Language Extensions specification https://github.com/ARM-software/acle/blob/main/main/acle.md#function-multi-versioning It supports new "target_version" function attribute and extends existing "target_clones" one. Also missing dependencies for target features were added. Differential Revision: https://reviews.llvm.org/D127812