bug#5569: 23.1.92; [ns] Latest visible-bell changes break the GNUstep build

[Yavor Doganov]

Package: emacs,ns

This change

2010-01-31  Filipe Cabecinhas  <filcab@gmail.com>  (tiny change)

        * nsterm.m (ns_ring_bell): Handle visible bell like X.

is not GNUstep-compatible:

nsterm.m:820: error: 'CGContextRef' undeclared (first use in this function)
nsterm.m:820: error: (Each undeclared identifier is reported only once
nsterm.m:820: error: for each function it appears in.)
nsterm.m:820: error: expected ';' before 'ctxt'
nsterm.m:821: error: 'CGRect' undeclared (first use in this function)
nsterm.m:821: error: expected ';' before 'lowerLine'
nsterm.m:822: error: 'lowerLine' undeclared (first use in this function)
nsterm.m:823: warning: implicit declaration of function 'CGRectMake'
nsterm.m:826: error: 'upperLine' undeclared (first use in this function)
nsterm.m:834: warning: implicit declaration of function 'CGContextSetBlendMode'
nsterm.m:834: error: 'ctxt' undeclared (first use in this function)
nsterm.m:834: error: 'kCGBlendModeDifference' undeclared (first use in this 
function)

In GNU Emacs 23.1.92.1 (i486-pc-linux-gnu, NS gnustep-gui-0.12.0)
 of 2010-02-11 on gana, modified for gNewSense
 (Unofficial gNewSense emacs-snapshot package, version 1:20100211-gns1)
Windowing system distributor `GNU', version 10.3.12
configured using `configure  '--build=i486-linux-gnu' '--prefix=/usr' 
'--sharedstatedir=/var/lib' '--libexecdir=/usr/lib' '--localstatedir=/var' 
'--infodir=/usr/share/info' '--mandir=/usr/share/man' '--with-pop=yes' 
'--enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/23.1.92/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.1.92/site-lisp:/usr/share/emacs/site-lisp'
 '--with-ns' '--disable-ns-self-contained' '--without-x' 
'build_alias=i486-linux-gnu' 'CFLAGS=-DDEBIAN -DSITELOAD_PURESIZE_EXTRA=5000 -g 
-Wall -Wno-pointer-sign -fno-crossjumping -I/usr/include/GNUstep -O2' 
'LDFLAGS=-g -Wl,-z,defs -Wl,--as-needed' 'CPPFLAGS=''