branches: 1.1.1.1.48; 1.1.1.1.60;
initial import of GCC 4.1 branch, from 2006-04-20. list of changes way
too large to list, but see:
http://gcc.gnu.org/gcc-3.4/changes.html
http://gcc.gnu.org/gcc-4.0/changes.html
http://gcc.gnu.org/gcc-4.1/changes.html
for the details.