types: missing 'long double' in psi_t_size() and psi_t_alignment()

[m6w6/ext-psi] / TODO

* avoid allocs inside structures by reallocating the whole structure
* let the various list types be hashtables where appropriate
* check out jit-dynamic
* fix arginfo with nullable types
* pemalloc
* CPP style #if(def(ined)) support in parser.re with a HashTable
* think about a better system for EXTVARs, separate \set and \get functions are clunky