test_mpi build: add comments to makefile for using ifx

Author: gforney

Utilities/test_mpi/makefile

@@ -44,6 +44,9 @@ impi_intel_win: MPILIB = "$(I_MPI_RELEASE_ROOT)\impi.lib"
 impi_intel_win: MPIINCLUDE = "$(IMPI_INCLUDE)"
 impi_intel_win: FFLAGS = /Qipo /O2 /I$(MPIINCLUDE) -fc=ifort
 impi_intel_win: FCOMPL = mpiifort
+#compilation crashes when using the following two lines instead of above two lines
+#impi_intel_win: FFLAGS = /Qipo /O2 /I$(MPIINCLUDE) -fc=ifx
+#impi_intel_win: FCOMPL = mpiifx
 impi_intel_win: obj = test_mpi
 impi_intel_win: setup_win $(objwin_mpi)
 	$(FCOMPL) -o $(obj) $(FFLAGS) /F1000000000 $(objwin_mpi) $(MPILIB)