autoconf 2.58 Fortran compiler list update

[Nelson H. F. Beebe]

In autoconf 2.58, ./lib/autoconf/fortran.m4 has a list of Fortran 77,
90, and 95 compilers that initialize _AC_F77_FC, _AC_F90_FC, and
_AC_F95_FC.

The _AC_F95_FC list contains ifc:

        #  ifc: Intel Fortran 95 compiler for Linux/x86

Effective yesterday with the release of version 8.0 of the Intel
Fortran compiler, the preferred name is now ifort, with ifc retained
for compatibility, but issuing a warning:

        % ifort hello.f90 && ./a.out
         hello ... This is a Fortran 90 program!

        % ifc hello.f90 && ./a.out
        ifc: warning: The Intel Fortran driver is now named ifort.  You can 
suppress this message with '-quiet'
         hello ... This is a Fortran 90 program!

In earlier releases, the IA-32 compiler was ifc, and the IA-64
compiler, efc.  From version 8.0, both are called ifort.

Please consider updating the list from

        m4_define([_AC_F95_FC], [f95 fort xlf95 ifc efc pgf95 lf95 gfortran])

to

        m4_define([_AC_F95_FC], [f95 fort xlf95 ifort ifc efc pgf95 lf95 
gfortran])

so that ifort is preferred over ifc.

Also, I think that pgf95 should be removed, since it doesn't exist.
See

        http://www.pgroup.com/faq/

The _AC_F90_FC list might possibly be augmented with pghpf, the
Portland Group High-Performance Fortran (a Fortran dialect based on
Fortran 90) compiler.

Please note that ./lib/autoconf/fortran.m4 is not the only file that
may need updates: I find mentions of Fortran compiler names in these
files:

        % egrep -l 
'\b(f77|xlf|cf77|cft77|pgf77|fl32|af77|fort77|f90|xlf90|pgf90|epcf90|f95|xlf95|lf95|g95|fc|fort|ifc|ifort)\b'
 `find . -type f`
        ./autoconf.m4f
        ./autoheader.m4f
        ./aclang.m4
        ./autoconf/fortran.m4
        ./autoconf/autoconf.m4f

It seems undesirable to me that such duplications are present, since
it makes maintenance error prone; for example, in the first of these,
I find

        AC_CHECK_TOOLS(F77,
              [m4_default([$1],
                          [g77 f77 xlf cf77 cft77 frt pgf77 fl32 af77 fort77 
f90 xlf90 pgf90 epcf90 f95 fort xlf95 lf95 g95 fc])])

-------------------------------------------------------------------------------
- Nelson H. F. Beebe                    Tel: +1 801 581 5254                  -
- Center for Scientific Computing       FAX: +1 801 581 4148                  -
- University of Utah                    Internet e-mail: address@hidden  -
- Department of Mathematics, 110 LCB        address@hidden  address@hidden -
- 155 S 1400 E RM 233                                                         -
- Salt Lake City, UT 84112-0090, USA    URL: http://www.math.utah.edu/~beebe  -
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