This patch adds NativeRegisterContext_arm64 ptrace routines to access AArch64 SVE registers. This patch also adds a test-case to test AArch64 SVE registers dynamic configuration and read/write.
This patch is part from previously submitted AArch64 SVE register access support.
At this point, that header is sufficiently different from the asm/ptrace.h implementation (names of all structs and fields are different) that I don't think it makes sense to use it as an optional replacement. It makes it very likely things will not build in one of the modes.
This should either use the system version (and then only build when the system has the appropriate headers), or we should use the in-house version unconditionally (which may require renaming/namespacing the rest of the file so that it does not conflict with the real asm/ptrace.h).