[Bug tree-optimization/127170] integer_pow2p supports Complex types; maybe remove it

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127170

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
I think it's good for consistency that integer_* predicates support all of
ANY_INTEGRAL_TYPE_P.  So I would rather not change that.

Maybe instead rename integer_pow2p to integer_cst_pow2p?  For some
reason it doesn't handle VECTOR_CST either.

Or rename all integer_* to [any_]integral_*?

Looking I see quite some inconsistencies :/