Define char16_t, char32_t consistently with uint_least16_t, uint_least32_t (bug 17979).

As noted in bug 17979 (and as I noted earlier in
<https://sourceware.org/ml/libc-alpha/2012-02/msg00647.html>), uchar.h
has gratuitously complicated code to determine the types for char16_t
and char32_t, and to reject including that header for pre-C11
compilers not defining __CHAR16_TYPE__ and __CHAR32_TYPE__.  Since
those types are always required to match uint_least16_t and
uint_least32_t, which glibc knows how to define without reference to
such predefined macros, it's safe just to define those types the same
as the *least* types are defined in stdint.h, so allowing the header
to work with (for example) GCC 4.3.

This patch implements that.  bits/types.h is made to define
__int_leastN_t and __uint_leastN_t so the logic for those types can
stay in a single place, and stdint.h is made to use those __*_t to
define the public *_t types.  uchar.h is then made to use
__uint_least16_t and __uint_least32_t to define char16_t and char32_t,
so simplifying the logic there.  A new test is added that verifies the
types chosen for char16_t and char32_t do indeed match the types the
compiler uses for u"" and U"" string literals.

Tested for x86_64.  (I have not tested with any of the older compilers
for which this would actually make a difference to whether you can
include uchar.h.)

	[BZ #17979]
	* posix/bits/types.h (__int_least8_t): New typedef.
	(__uint_least8_t): Likewise.
	(__int_least16_t): Likewise.
	(__uint_least16_t): Likewise.
	(__int_least32_t): Likewise.
	(__uint_least32_t): Likewise.
	(__int_least64_t): Likewise.
	(__uint_least64_t): Likewise.
	* sysdeps/generic/stdint.h (int_least8_t): Define using
	__int_least8_t.
	(int_least16_t): Define using __int_least16_t.
	(int_least32_t): Define using __int_least32_t.
	(int_least64_t): Define using __int_least64_t.
	(uint_least8_t): Define using __uint_least8_t.
	(uint_least16_t): Define using __uint_least16_t.
	(uint_least32_t): Define using __uint_least32_t.
	(uint_least64_t): Define using __uint_least64_t.
	* wcsmbs/uchar.h: Include <bits/types.h>.
	(char16_t): Define using __uint_least16_t conditional only on
	[!__USE_ISOCXX11].
	(char32_t): Define using __uint_least32_t conditional only on
	[!__USE_ISOCXX11].
	* wcsmbs/test-char-types.c: New file.
	* wcsmbs/Makefile (tests): Add test-char-types.

1 files changed, 10 insertions, 0 deletions

diff --git a/posix/bits/types.h b/posix/bits/types.h
index bd06e2d17e..5e22ce41bf 100644
--- a/posix/bits/types.h
+++ b/posix/bits/types.h
@@ -47,6 +47,16 @@ __extension__ typedef signed long long int __int64_t;
 __extension__ typedef unsigned long long int __uint64_t;
 #endif
 
+/* Smallest types with at least a given width.  */
+typedef __int8_t __int_least8_t;
+typedef __uint8_t __uint_least8_t;
+typedef __int16_t __int_least16_t;
+typedef __uint16_t __uint_least16_t;
+typedef __int32_t __int_least32_t;
+typedef __uint32_t __uint_least32_t;
+typedef __int64_t __int_least64_t;
+typedef __uint64_t __uint_least64_t;
+
 /* quad_t is also 64 bits.  */
 #if __WORDSIZE == 64
 typedef long int __quad_t;