Add restrict annotations to all functions that require it

[Joseph Myers]

On Sat, 3 Dec 2022, Alejandro Colomar via Libc-alpha wrote:

> For example, this would be nonsense (and I honestly don't know what the
> compiler would understand from it):
> 
> void broken(int *restrict a, int *b, int *c);
> void broken(int *a, int *restrict b, int *c);

Qualifiers on parameters in a function declarator that is not part of a 
definition of that function have no semantic effect; restrict on function 
parameters only has a semantic effect in the definition of the function.

-- 
Joseph S. Myers
joseph@codesourcery.com