Update l3trial symbolic expressions after recent changes to l3fp

The work on l3fp-functions is not done, hence the failing test
m3fp-functions001.  This should not prevent a CTAN upload.


git-svn-id: http://www.latex-project.org/svnroot/experimental/trunk@4606 de43f980-851b-0410-b2f7-c40aca1f87e0