I want to use other g++ in "make test"

I use CentOS5. I install new version g++ as g++44 to compile llvm.

Tests is succeed if i change the following part in Makefile.PL.

```
makemaker_args->{CC} = 'g++44';
makemaker_args->{LD} = 'g++44';
```

Can you change this part to select CC and LD by user?
