* renamed several helpers so that their name is the same as their
"public alias", which should facilitate the conversion of processor
specific code in the code generator to processor independent code
* some small fixes to the val_ansistring and val_widestring helpers
(always immediately exit if the source string is longer than 255
chars)
* fixed fpc_dynarray_high and fpc_dynarray_length if the dynarray is
still nil (used to crash, now return resp -1 and 0)