Enable /GL.  It seems to help about 10%.

svn path=/trunk/tools/build/v2/; revision=83921
Tweak type.is-derived.

svn path=/trunk/tools/build/v2/; revision=83922
Don't let python write .pyc files.  They might not be updated, if the test runs too fast.

svn path=/trunk/tools/build/v2/; revision=83923