Thank you for the prompt suggestion in compiling llvm-gcc. I have just tried the following:
llvm-gcc4.2-2.1-source$ make clean
llvm-gcc4.2-2.1-source$ ./configure --disable-multilib --disable-shared --enable-languages=c,c++
llvm-gcc4.2-2.1-source$ make -j32
And still the code for Java is compiled and clashes with others in the linker. I have tried removing the ./gcc/java folder and then it fails at stage-1. I guess I missed some tricks disabling Java compilation.
Once again, thank you for your help.