GMP 4.3.1 fails check when --enable-cxx is used

[Shlomo Mahlab]

I'm trying to compile GMP on a SunOS 5.10 machine, using gcc 4.4.1.
configuring without --enable-cxx pass build and check with no issues.
adding the --enable-cxx config option (required by PPL package) breaks 
the check stage with the following error.
I couldn't find any reference to the required link library in Goggle.
Shlomo

Undefined                       first referenced
symbol                             in file
__sync_fetch_and_add_4              t-assign.o
ld: fatal: Symbol referencing errors. No output written to .libs/t-assign
collect2: ld returned 1 exit status
make[4]: *** [t-assign] Error 1
make[4]: Leaving directory `.../gmp-4.3.1/tests/cxx'