link_warning fix

[Bruno Haible]

Roland McGrath writes:

> > 	* include/libc-symbols.h (__as_app_line, __as_noapp): New macros.
> > 	(link_warning): Emit #APP line to turn comment recognition on, and
> > 	turn it off afterwards.
> 
> I am confused as to why this should be necessary.
> GCC has always emitted "#APP" and "#NO_APP" around the asm text.

Yes, and the purpose of the __as_noapp macro is precisely to get gcc
into emitting "#NO_APP".

It is necessary in the first place because #APP is turned on through a
strange sectionname in

    static const char <variable> __attribute__ ((section ("<sectionname>")));

for which gcc does not emit #NO_APP automatically by itself.

Bruno