RFR: 8247910: Improve alignment and power-of-2 utilities using C++14

[Thomas Schatzl]

Hi,

On 11.09.20 10:50, Kim Barrett wrote:
> Please review this change which updates the alignment and power-of-2
> utilities (utilities/align.hpp and utilities/powerOfTwo.hpp) to use
> C++14 features.
> 
> Where possible, the alignment functions are now constexpr.  This
> eliminates the need for alternate macros that needed to be used in
> constexpr contexts.
> 
> Use <type_traits> and <limits> rather than HotSpot workalikes.
> We no longer need max_value<T>(), as the problematic platform for
> std::numeric_limits<T>::max() was Solaris.
> 
> Testing: tier1
> 

in utilities/align.hpp:63:

  62 constexpr T align_down(T size, A alignment) {

The comment mentions "lognot" twice, at least it took me a while to 
understand that it is an abbreviation for "logical not". Probably it's 
common in LISP context?. I still think it might be worth just typing it 
out for easier reading.

If you think it's better to keep lognot, fine with me too, I'll mark 
this as reviewed.

Thanks,
   Thomas