update Wextra doc

[Manuel López-Ibáñez]

:ADDPATCH doc:

The manual page claims that Wextra warns for any of several
floating-point events that often indicate errors, such as overflow,
underflow, loss of precision, etc. I wasn't able to find any instance
of this. I am fairly sure that Wextra doesn't do such thing.

This patch is in accordance with the discussion about fixing PR7651.
See http://gcc.gnu.org/ml/gcc/2007-01/msg00391.html

OK for mainline?
Should this change also go into 4.2 ?

2007-02-10  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>

  * doc/invoke.texi (Wextra): Delete outdated paragraph.
-------------- next part --------------
Index: gcc/doc/invoke.texi
===================================================================
--- gcc/doc/invoke.texi	(revision 121678)
+++ gcc/doc/invoke.texi	(working copy)
@@ -2961,10 +2961,6 @@ A pointer is compared against integer ze
 A variable might be changed by @samp{longjmp} or @samp{vfork}.
 This warning can be independently controlled by @option{-Wclobbered}.
 
-@item
-Any of several floating-point events that often indicate errors, such as
-overflow, underflow, loss of precision, etc.
-
 @item @r{(C++ only)}
 An enumerator and a non-enumerator both appear in a conditional expression.