Philippe 11/01/2022: use -traditional cpp flag only when useful + create CPPFLAGS_C

src/Makefile

-#MNH_LIC Copyright 1994-2021 CNRS, Meteo-France and Universite Paul Sabatier
+#MNH_LIC Copyright 1994-2022 CNRS, Meteo-France and Universite Paul Sabatier
 #MNH_LIC This is part of the Meso-NH software governed by the CeCILL-C licence
 #MNH_LIC version 1. See LICENSE, CeCILL-C_V1-en.txt and CeCILL-C_V1-fr.txt
 #MNH_LIC for details. version 1.
@@ -565,7 +565,7 @@ ARFLAGS=r
 	-mv  $(*F).o $(OBJDIR)/. || echo OK $(*F).o
 
 %.o : %.c
-	$(CC) $(INC) $(CFLAGS) $(CPPFLAGS) -c $< -o $(OBJDIR)/$(*F).o
+	$(CC) $(INC) $(CFLAGS) $(CPPFLAGS_C) -c $< -o $(OBJDIR)/$(*F).o
 	-mv  $(*F).o $(OBJDIR)/. || echo OK $(*F).o
 
 ifeq "$(DO_COMP_MASTER)" "YES"

src/Rules.LXcray.mk

-#MNH_LIC Copyright 1994-2021 CNRS, Meteo-France and Universite Paul Sabatier
+#MNH_LIC Copyright 1994-2022 CNRS, Meteo-France and Universite Paul Sabatier
 #MNH_LIC This is part of the Meso-NH software governed by the CeCILL-C licence
 #MNH_LIC version 1. See LICENSE, CeCILL-C_V1-en.txt and CeCILL-C_V1-fr.txt
 #MNH_LIC for details. version 1.
@@ -120,13 +120,15 @@ LDFLAGS    =   -Wl,-warn-once $(PAR) $(OPT_BASE)
 #
 # preprocessing flags 
 #
-CPP = cpp -P -traditional -Wcomment
+#CPP = /bin/cpp -P -traditional -Wcomment
+CPP = cpp -P -Wcomment
 #
-CPPFLAGS_SURFEX    =
-CPPFLAGS_SURCOUCHE = -DDEV_NULL -DUSE_MPI
-CPPFLAGS_RAD       =
-CPPFLAGS_NEWLFI    = -DSWAPIO -DLINUX -DLFI_INT=${LFI_INT}
-CPPFLAGS_MNH       = -DMNH -DSFX_MNH -DMNH_NO_MPI_LOGICAL48 -DUSE_MPI -DMNH_CRAY
+CPPFLAGS_C         = -DLITTLE_endian
+CPPFLAGS_SURFEX    = -traditional
+CPPFLAGS_SURCOUCHE = -traditional -DDEV_NULL -DUSE_MPI
+CPPFLAGS_RAD       = -traditional
+CPPFLAGS_NEWLFI    = -traditional -DSWAPIO -DLINUX -DLFI_INT=${LFI_INT}
+CPPFLAGS_MNH       = -traditional -DMNH -DSFX_MNH -DMNH_NO_MPI_LOGICAL48 -DUSE_MPI -DMNH_CRAY
 ifdef VER_GA
 CPPFLAGS_SURCOUCHE += -DMNH_GA
 INC                += -I${GA_ROOT}/include