Multiversion 0.7.0

Changed

• The multiversion macro has been overhauled. Now uses a single attribute macro, rather than helper attributes.
• Increased minimum required Rust version to 1.61.0.

Added

• The function dispatch method is now selectable, between direct or indirect dispatch, as well as compile-time static dispatch.
• Added a variety of macros in the multiversion::target module for querying the selected target features.
• Targets can now be specified by CPU (e.g. x86-64-v2 or skylake).
• Added option to pass attributes to clones.
• Added special targets = "simd" option to automatically target all SIMD instruction sets.

Removed

• Removed the specialize mode. All targets now specify clones. Specialization should be implemented by querying the selected targets.
• Removed support for functions that reference self or Self. Previous support was inconsistent and difficult to use correctly.

Fixed

• Fixed broken impl Trait support. Using impl Trait in return position now results in an error.
• Dispatch is now bypassed in scenarios where no targets are specified for the target architecture, or if the first matching target features are known to exist at compile time.
• Improved performance of direct dispatch.
• Avoid indirect dispatch in some situations, such as when using retpolines