Add PVSIZE function to return the size of a pseudovector.

Add PVSIZE function to return the size of a pseudovector.

* src/lisp.h (PVSIZE): New function.

* src/chartab.c (copy_char_table):
* src/data.c (Ftype_of, Finteractive_form, Faref, Faset):
* src/doc.c (Fdocumentation, store_function_docstring):
* src/eval.c (Fcommandp, funcall_lambda, lambda_arity, Ffetch_bytecode):
* src/fns.c (Flength, Fcopy_sequence):
* src/font.h (FONT_SPEC_P, FONT_ENTITY_P, FONT_OBJECT_P):
* src/lread.c (substitute_object_recurse):
* src/src/print.c (print_object):
  Use it.