Make use of Data-Independent Timing (DIT) on Arm

[tgross35]

trafficstars

aarch64 supports data-independent timing https://developer.arm.com/documentation/ddi0595/2020-12/AArch64-Registers/DIT--Data-Independent-Timing, which is also available on Apple silicon https://developer.apple.com/documentation/xcode/writing-arm64-code-for-apple-platforms#Enable-DIT-for-constant-time-cryptographic-operations. Would it be advantageous to make use of the feature in this crate?