v1.20.1
[arm] Provide dummy implementations for {in,out}[s]{b,w,l}
[build] Fix ARM32 EFI builds with current EDK2 headers
[build] Conditionalise use of -mabi=lp64 for ARM64 builds
[build] Use -no-pie on newer versions of gcc
[init] Show startup and shutdown function names in debug messages
[build] Prevent use of MMX and SSE registers