adaptive aligned array based struct tvec type

[jopadan]

Switch to C++26 include all the glmark2 changes and add adaptive array based tvec type while preserving the exposed interface.

/* vector align non-power of 2 element count */ 
tvec<float, 3, align::vector> a = {1,2,3};
/* use default adaptive alignment */
tvec<float, 3> b = {1,2,3};
tvec<float, 4> c = {1,2,3,4};
/* element align power of 2 element count */
tvec<float, 4, align::element>  d = {1,2,3,4};

cnt/typ/alg/sze
  3/  4/ 16/ 16: vector
  3/  4/  4/ 12: adaptive
  4/  4/ 16/ 16: adaptive
  4/  4/  4/ 16: element