Re: linker warnings

[Tom Spindler <dogcow%babymeat.com@localhost>]

>   | How about add following lines, too?
>   | 
>   | CFLAGS+= -Wa,--fatal-warnings
>   | AFLAGS+= -Wa,--fatal-warnings
>   | 
>   | These are very useful to debug delay slot problem on mips...
> 
> I think this has merit.
> 
> It could be controlled by either !defined(NOGCCERROR),
> or an appropriate level of WARNS.

All non-MIPS arches I've tried compile OK with that flag - but MIPS
dies when trying to compile lib/libc/mcount.c with PIC:
/tmp/ccM2AZVL.s: Assembler messages:
/tmp/ccM2AZVL.s:9: Warning: No .cprestore pseudo-op used in PIC code
/tmp/ccM2AZVL.s:219: Error: 1 warnings, treating warnings as errors

This comes from src/sys/arch/mips/include/profile.h and the MCOUNT
and _PROF_CPLOAD macros:

#ifdef _KERNEL
# define _PROF_CPLOAD   ""
#else
# define _PROF_CPLOAD   ".cpload $25;"
#endif

This test should perhaps include something testing for PIC or not.