strfmon_l: Fix -fsanitize=address finding. * lib/strfmon_l.c: Include <errno.h>, <stdbool.h>, <stdlib.h>, <string.h>. (MAX_ARGS): Renamed from MAX_ARG_WORDS. (directive_t, directives_t): New types. (fmon_parse): New function. (rpl_strfmon_l): Don't call va_arg more often than needed for the format string. Consume 'long double' arguments in places where the format string indicates so. * modules/strfmon_l (Depends-on): Add 'stdbool'.

Files:
tests/test-isnanl.c
tests/test-isnanl.h
tests/minus-zero.h
tests/infinity.h
tests/nan.h
tests/macros.h

Depends-on:
float

configure.ac:
gl_LONG_DOUBLE_EXPONENT_LOCATION
AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])

Makefile.am:
TESTS += test-isnanl
check_PROGRAMS += test-isnanl
test_isnanl_LDADD = $(LDADD) @ISNANL_LIBM@