[Bug libstdc++/59974] ostream crashes on large numbers under Windows

[steve at sk2 dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59974

--- Comment #1 from Stephen Kitt <steve at sk2 dot org> ---
Created attachment 31973
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31973&action=edit
Proposed patch