Add #include directives to fix these errors:
[CC] src/intl/gettext/l10nflist.o
cc1: warnings being treated as errors
.../src/intl/gettext/l10nflist.c: In function ‘_nl_normalize_codeset’:
.../src/intl/gettext/l10nflist.c:352: error: implicit declaration of function ‘c_tolower’
[CC] src/dom/css/scanner.o
cc1: warnings being treated as errors
In file included from .../src/dom/scanner.h:4,
from .../src/dom/css/scanner.h:4,
from .../src/dom/css/scanner.c:12:
.../src/dom/string.h: In function ‘dom_string_casecmp’:
.../src/dom/string.h:34: error: implicit declaration of function ‘c_strncasecmp’