v0.7.0

Added

• New InterruptNumber trait is now required on interrupt arguments to the
  various NVIC functions, replacing the previous use of Nr from bare-metal.
  For backwards compatibility, InterruptNumber is implemented for types
  which are Nr + Copy, but this will be removed in a future version.
• Associated const PTR is introduced to Core Peripherals to
  eventually replace the existing ptr() API.
• A delay driver based on SysTick.
• You can now use LTO to inline assembly calls, even on stable Rust.
  See the asm/lib.rs documentation for more details.
• Initial ARMv8-M MPU support
• ICTR and ACTLR registers added
• Support for the Security Attribution Unit on ARMv8-M

Changed

• Previously, asm calls without the inline-asm feature enabled used pre-built
  objects which were built by a GCC compiler, while inline-asm enabled the
  use of llvm_asm! calls. The asm system has been replaced with a new
  technique which generates Rust static libs for stable calling, and uses the
  new asm! macro with inline-asm. See the asm/lib.rs documentation for
  more details.
• Cache enabling now uses an assembly sequence to ensure correctness.
• ptr() methods are now const.

Breaking Changes

• SCB::invalidate_dcache and related methods are now unsafe, see #188
• Peripherals struct is now non-exhaustive, so fields may be added in future
  non-breaking changes
• Removed aligned dependency
• Removed const-fn feature
• Removed previously deprecated APIs
  • NVIC::clear_pending
  • NVIC::disable
  • NVIC::enable
  • NVIC::set_pending
  • SCB::system_reset
• Removed basepri, basepri_max, and faultmask registers from thumbv8m.base