Fix compile on Cygwin (#2003)

TYPE: bug fix

KEYWORDS: compilation, Cygwin, doc files

SOURCE:  Daniel Wesloh (Penn State)

DESCRIPTION OF CHANGES:
Problem:
Compiling WRF failed on Cygwin due to lack of netCDF4

Solution:
Match assumptions about `USENETCDFPAR` (#1743 would also fix this) and pass flags to allow legacy Fortran constructs (disallowed by default with GCC 10)

ISSUE: For use when this PR closes an issue.
Fixes #1271

LIST OF MODIFIED FILES: 
M       configure
M       doc/README.cygwin.md
M       doc/README.netcdf4par

TESTS CONDUCTED: 
1. Checked whether model compiles on Cygwin in DWesl#1
2. The Jenkins tests have passed.

RELEASE NOTE: Fix compilation on Cygwin.

configure

@@ -59,7 +59,7 @@ if `pwd | grep ' ' > /dev/null ` ; then
  echo and this may cause problems for your build. This can occur, for example, on
  echo Windows systems. It is strongly recommended that you install WRF and other
  echo related software such as NetCDF in directories whose path names contain no
- echo white space. On Win, for example, create and install in a directory under C:.
+ echo white space. On Windows, for example, create and install in a directory under C:.
  echo '*****************************************************************************'
 fi
 
@@ -659,7 +659,7 @@ fi
 #Checking cross-compiling capability for some particular environment
 #on Linux and Mac box
 
-if [ $os = "Linux" -o $os = "Darwin" ]; then
+if [ $os = "Linux" -o $os = "Darwin" -o $os = "CYGWIN_NT" ]; then
 
  SFC=`grep '^SFC' configure.wrf | awk '{print $3}'`
  SCC=`grep '^SCC' configure.wrf | awk '{print $3}'`

doc/README.cygwin.md

@@ -17,11 +17,28 @@
   - gcc-core (OpenMP for smpar)
   - gcc-fortran
   - libnetcdf-fortran-devel
+  - libnetcdf-devel
+  - libhdf5-devel
+  - zlib-devel
   - openmpi (MPI for dmpar)
   - libopenmpi-devel (MPI for dmpar)
+  - libhwloc-devel (MPI for dmpar)
+  - libevent-devel (MPI for dmpar)
   - libjasper-devel (GRIB)
   - perl
+  - perl_base
   - tcsh
+  - m4
+  - make
+  - libtirpc-devel
+  - sed
+  - gawk
+  - tar
+  - gzip
+  - coreutils
+  - which
+  - file
+  - grep
  - Select install
  - Accept the packages pulled in as dependencies
  - Wait for download, install, and postinstall steps. This will

doc/README.netcdf4par

@@ -41,4 +41,4 @@ Performance seems to vary with how 'regular' the domain decomposition is
 (i.e., patch size). Some experimentation with manually setting the decomposition
 may be needed for optimal writing times. Also pay attention to file system 
 striping (Lustre), where setting the number stripes should not exceed the
-number of nodes used by the job.
+number of nodes used by the job.