libobjc: updated documentation for removal of traditional API

[Nicola Pero]

This patch (trivially) updates the libobjc documentation to state
that the Traditional Objective-C runtime API is no longer available.

Committed to trunk.

Thanks

Index: ChangeLog
===================================================================
--- ChangeLog   (revision 174821)
+++ ChangeLog   (working copy)
@@ -1,3 +1,8 @@
+2011-06-09  Nicola Pero  <nicola.pero@meta-innovation.com>
+
+       * doc/objc.texi (Traditional GNU Objective-C runtime API):
+       Updated.
+
 2011-06-08  Alexandre Oliva  <aoliva@redhat.com>
 
        * tree-flow-inline.h (op_iter_init): Reject GIMPLE_PHI stmts.
Index: doc/objc.texi
===================================================================
--- doc/objc.texi       (revision 174821)
+++ doc/objc.texi       (working copy)
@@ -121,25 +121,9 @@ different naming convention, such as @code{class_g
 API).  Software using this API includes the file
 @file{objc/objc-api.h} where it is declared.
 
-The traditional API is deprecated but it is still supported in this
-release of the runtime; you can access it as usual by including
-@file{objc/objc-api.h}.
+Starting with GCC 4.7.0, the traditional GNU runtime API is no longer
+available.
 
-If you are using the traditional API you are urged to upgrade your
-software to use the modern API because the traditional API requires
-access to private runtime internals to do anything serious with it;
-for this reason, there is no guarantee that future releases of the GNU
-Objective-C runtime library will be able to provide a fully compatible
-@file{objc/objc-api.h} as the private runtime internals change.  It is
-expected that the next release will hide a number of runtime internals
-making the traditional API nominally supported but fairly useless
-beyond very simple use cases.
-
-Finally, you can not include both @file{objc/objc-api.h} and
-@file{objc/runtime.h} at the same time.  The traditional and modern
-APIs unfortunately have some conflicting declarations (such as the one
-for @code{Method}) and can not be used at the same time.
-
 @c =========================================================================
 @node Executing code before main
 @section @code{+load}: Executing code before main