Fix strtol in Turkish locales (bug 19242).

Fix strtol in Turkish locales (bug 19242).

The implementations of strtol and related functions use
locale-specific conversions to upper case before determining whether a
character is a valid letter in the argument.  This means that in
Turkish locales such as tr_TR.UTF-8 and tr_TR.ISO-8859-9, "i" is
interpreted as not being a valid number, when if the base passed to
strtol is 19 or more it should be interpreted as the number 18.

ISO C explicitly says "The letters from a (or A) through z (or Z) are
ascribed the values 10 through 35", so clearly intends the standard
ASCII letters (otherwise you wouldn't generally have exactly 26
letters to ascribe such values) (whereas white-space must be
identified according to the locale).  In particular, 'i' and 'I' must
be understood to be in that sequence.

This patch makes the code do the case conversions and classification
in the C locale; the user's locale remains used for whitespace testing
(explicitly correct according to ISO C).  Note that the way the code
worked, the only non-ASCII letter that would previously have been
accepted would have been the Turkish 'ı' (dotless 'i'), because the
uppercase version of that in Turkish locales is 'I'.  This patch means
that will no longer be accepted, which seems appropriate.

Tested for x86_64 and x86.

	[BZ #19242]
	* stdlib/strtol_l.c (ISALPHA): Use _nl_C_locobj_ptr for locale.
	(TOUPPER): Likewise.
	* stdlib/tst-strtol-locale-main.c: New file.
	* stdlib/tst-strtol-locale.c: Likewise.
	* stdlib/Makefile (tests): Add tst-strtol-locale.
	[$(run-built-tests) = yes] (LOCALES): Add tr_TR.ISO-8859-9.
	[$(run-built-tests) = yes] ($(objpfx)tst-strtol-locale.out):
	Depend on $(gen-locales).
	* wcsmbs/tst-wcstol-locale.c: New file.
	* wcsmbs/Makefile (tests): Add tst-wcstol-locale.
	[$(run-built-tests) = yes] (LOCALES): Add tr_TR.UTF-8 and
	tr_TR.ISO-8859-9.
	[$(run-built-tests) = yes] ($(objpfx)tst-wcstol-locale.out):
	Depend on $(gen-locales).