recent work on include/bits/locale_facets.h

[Loren James Rittle]

Would someone that recently worked on include/bits/locale_facets.h
consider the direct use of a char (which may be unsigned or signed,
depending on platform) to index both _M_widen and _M_narrow in the new
code path.

The daily tester on ref5 compiles testsuite/17_intro/headers.cc with
-Wall -Wsystem-headers and thus caught this issue:

[...]locale_facets.h:881: warning: array subscript has type `char'
[...]locale_facets.h:937: warning: array subscript has type `char'
[...]locale_facets.h:937: warning: array subscript has type `char'
[...]locale_facets.h:939: warning: array subscript has type `char'

Regards,
Loren