Because our tests now have several places where FIXNUM_MAX is needed,
we decided to provide it along with several other constants.

	* template/limits.c.tmpl: new file, defining RbConfig::Limits

	* ext/rbconfig/sizeof/depend (limits.c): rule to generate limits.c

	* test/-ext-/num2int/test_num2int.rb: use RbConfig::Limits

	* bootstraptest/test_insns.rb: ditto.

	* .gitignore: ignore new generated file.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57465 b2dd03c8-39d4-4d8f-98ff-823fe69b080e