Segregate aliases to DEFVAR_CONST

Segregate aliases to DEFVAR_CONST

	* lisp/float-sup.el: Remove alias for pi and e when bigfr is
	available. These should now be defined in const-aliases, loaded
	by startup.

	* lisp/const-aliases.el (pi): Define const as bigfr-pi when bigfr
	is available.
	(e): Define as euler when bigfr is available.

	* lisp/Makefile.am (corelispels): Add const-aliases.el to list of
	files.

	* lisp/startup.el (load-init-file): Require new const-aliases to
	load the consts that cannot be dumped.

Signed-off-by: Nelson Ferreira <nelson.ferreira@ieee.org>