Tru64 4.0D declares round* but does not define them

[Ralf Wildenhues]

Hello,

On Tru64 4.0D, /usr/include.dtk/math.h declares round, roundf and
roundl, but I can't find a library that defines them.  Same thing for
roundf and roundl and respective tests.

This causes link failures for the test-round* tests:

| source='../../dummy-0/gltests/test-round1.c' object='test-round1.o' 
libtool=no \DEPDIR=.deps depmode=tru64 /bin/ksh 
../../dummy-0/gltests/../build-aux/depcomp \cc -DHAVE_CONFIG_H -I. 
-I../../dummy-0/gltests  -I. -I../../dummy-0/gltests -I.. 
-I../../dummy-0/gltests/.. -I../gllib -I../../dummy-0/gltests/../gllib -ieee  
-g -c ../../dummy-0/gltests/test-round1.c
| cc: Info: ../gllib/math.h, line 210: In this declaration, type long double 
has the same representation as type double on this platform. (longdoublenyi)
| extern long double frexpl (long double x, int *expptr);
| -------^
| cc: Warning: ../../dummy-0/gltests/test-round1.c, line 84: In this statement, 
division by zero occurs in evaluating the expression "1.0/0.0". (zerodiv)
|   ASSERT (round (1.0 / 0.0) == 1.0 / 0.0);
| --^
[...]
| cc  -g   -o test-round1 test-round1.o ../gllib/libgnu.a  -lm
| ld:
| Unresolved:
| round

Cheers,
Ralf