[libc++] Fix segmentation fault in __do_put_integral

6 chars are not sufficient to represent all formats for 64 bit integers.

This was accidentally introduced in commit b889cbf36635a302f5b77560f1769178f196c2c7 (https://reviews.llvm.org/D112830).

This causes failures in downstream projects, for example:

* https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=40817
* https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=40841

Differential Revision: https://reviews.llvm.org/D113600

GitOrigin-RevId: faa019c0e38e8cb33d7e7fee92aa548bd052939e
1 file changed