[tree-ssa] Can't build because libmudflap needs C++

[Steven Bosscher]

Hi,

It has been impossible to build the tree-ssa branch without building C++
for a couple of weeks now.  This is really annoying.  I usually just
want to build C and F95 and I have seen other people who tried to build
the tree-ssa branch without C++, too.

Not everybody is interested in C++ or mudflap.  Also, this library
should just not depend on C++ to be build, or building should be
disabled if you don't configure with --enable-languages=c++.

Can it be fixed please.

Greetz
Steven