PR44684: Look through parens and similar constructs when determining

PR44684: Look through parens and similar constructs when determining
whether a call is to a builtin.

We already had a general mechanism to do this but for some reason
weren't using it. In passing, check for the other unary operators that
can intervene in a reasonably-direct function call (we already handled
'&' but missed '*' and '+').

This reverts commit aaae6b1b617378362462c1685e754813ed82b394,
reinstating af80b8ccc5772c14920d4554b7ca7e15f2fad1c4, with a fix to
clang-tidy.