manual: Refactor documentation of CHAR_BIT.

[Rical Jasan <ricaljasan at pacific dot net>]

This single-@item @table is better defined with @defvr, since the
CHAR_BIT macro has @standards (being declared in a header), and @items
in @tables are not considered annotatable.  Using @defvr automatically
includes the macro in the Variable and Constant Macro Index and
ensures its inclusion the Summary of Library Facilities.  The file
include/limits.h identifies the macro as coming from C99.

	* manual/lang.texi (CHAR_BIT): Convert from an @table to an
	@defvr.  Change standard from ISO to C99.
---
 manual/lang.texi | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/manual/lang.texi b/manual/lang.texi
index cf0e4e73cd..4b04232e3c 100644
--- a/manual/lang.texi
+++ b/manual/lang.texi
@@ -629,9 +629,8 @@ There is no operator in the C language that can give you the number of
 bits in an integer data type.  But you can compute it from the macro
 @code{CHAR_BIT}, defined in the header file @file{limits.h}.
 
-@table @code
-@item CHAR_BIT
-@standards{ISO, limits.h}
+@defvr Macro CHAR_BIT
+@standards{C99, limits.h}
 This is the number of bits in a @code{char}---eight, on most systems.
 The value has type @code{int}.
 
@@ -641,7 +640,7 @@ this:
 @smallexample
 sizeof (@var{type}) * CHAR_BIT
 @end smallexample
-@end table
+@end defvr
 
 That expression includes padding bits as well as value and sign bits.
 On all systems supported by @theglibc{}, standard integer types other