* eval.c (set_method_visibility): should have clear cache forq
updated visibility.
* numeric.c (flo_to_s): default format precision to be "%.16g".
* util.c (ruby_strtod): use own strtod(3) implementation to avoid
locale hell. Due to this change "0xff".to_f no longer returns 255.0
* eval.c (avalue_to_yvalue): new function to distinguish yvalue
(no-arg == Qundef) from svalue (no-arg == Qnil).
* eval.c (rb_yield_0): use avalue_to_yvalue().
* eval.c (assign): warn if val == Qundef where it means rhs is
void (e.g. yield without value or call without argument).
* parse.y (value_expr): need not to warn for WHILE and UNTIL,
since they can have return value (via valued break).
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@2457 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
