bug#63323: c-ts-mode does not know about `restrict'

[Po Lu]

Standard C accepts a keyword `restrict', which is used to declare
pointers whose referenced object must only be accessed by lvalues based
upon one such pointer within the block where they are declared.

Like so:

  argb *restrict src, *restrict dest;

c-ts-mode does not understand this keyword.  It is not fontified within
such declarations.