[PATCH v3] libstdc++: Fix SIGSEGV in std::print with a setvbuf'd FILE

[Anlai Lu]

Hi Tomasz,

Thanks a lot for polishing the patch and testing it! The
_M_init_write_buf restructure is much cleaner. The
current version looks good to me.

One minor thing: there are two small typos in the ChangeLog entry
("separte" should be "separate", and "_M_writebuf" should be
"_M_write_buf").

Thanks again!
Anlai