…ke (#2637)

find src -type f -perm /a+x -name '*.h' -print0 | xargs --null chmod -x

The order depends on whether you're enabling or disabling

* Update sha256_alt.h

Fix trivial copy-paste error in comment

* Update README.md

Another small typo in documentation

Fix copy-paste-error. With RP2350's Hazard3 should never show up, but anyway.

The sideset_bit_count in pio_encode_sideset_opt is unsigned, so any comparison
"sideset_bit_count >= 0" will always be true.  GCC with pedantic warnings
will complain when this happens.

Remove the unneeded >=0 portion of the parameter validity check.

Fixes #2607

Since ARM hosts have builtins listed in hardware/sync.h, these builtins
should be clobbered. Newer versions of LLVM/Clang emit an error when
clobbering these builtins, so this switches the overrides to use the
same patterns as pico_atomic to clobber the builtins.

…2632)

Partially fixes #2630, as it doesn't take care of the required delay between setting the LED

If the compiler in use offers __sev(), __wfe(), or __wfi(), forward
declare them to be sure they're available for use.