The commit "Test all target types in Fortran" enabled a SHARED library
in the Fortran test. However, we do not yet implement support for
shared libraries with XL Fortran (it seems this requires using the C
compiler to link). Furthermore, the old g77 2.97 from Red Hat does not
support shared libs on Itanium because the g2c lib is not -fPIC.
For now we just disable SHARED libs in the test for these tools.