cygwin g++ failures `::acosf' undeclared (first use here)

["Billinghurst, David (CRTS)" <David dot Billinghurst at riotinto dot com>]

Around 10 of my g++ testsuite failures on cygwin due to the use of the
compiler option "-ansi" in the g++ testsuite.

The failures are of the form: 

In file included 
	from <...>/include/bits/std_complex.h:43,                  
	from <...>/libstdc++-v3/include/complex:31,
	from <...>/g++.brendan/crash20.C:3:
<...>/std_cmath.h: In function `float std::acos(float)':
<...>/std_cmath.h:95: `::acosf' undeclared (first use here) 
<...>/std_cmath.h: In function `float std::asin(float)':  
... /std_cmath.h:113: `::asinf' undeclared (first use here)
... /std_cmath.h: In function `float std::atan(float)':
... /std_cmath.h:131: `::atanf' undeclared (first use here)

and so on.

In /usr/include/math.h the declaration of the these functions is guarded by 
#ifndef __STRICT_ANSI__
#endif
which seems reasonable

but the command line used to run the test has the flag "-ansi" 

/usr/local/obj/gcc-ec/gcc/testsuite/../g++ --verbose -save-temps
-B/usr/local/obj/gcc-ec/gcc/testsuite/../  -nostdinc++
-I/usr/local/obj/gcc-ec/i686-pc-cygwin/libstdc++-v3/include/i686-pc-cygwin
-I/usr/local/obj/gcc-ec/i686-pc-cygwin/libstdc++-v3/include
-I/usr/local/src/gcc/libstdc++-v3/libsupc++
-I/usr/local/src/gcc/libstdc++-v3/libio
-I/usr/local/src/gcc/libstdc++-v3/testsuite -fmessage-length=0
-pedantic-errors -Wno-long-long  -c  -o
/usr/local/obj/gcc-ec/gcc/testsuite/crash20.o
/usr/local/src/gcc/gcc/testsuite/g++.old-deja/g++.brendan/crash20.C


Any ideas?