Fix ifs compilation

.gitignore

@@ -1,3 +1,7 @@
+*.o
+*.mod
+*.dep-f90
+*.a
 sources/oasis3-mct/ecconf/
 sources/xios-2.5/.cache/
 sources/xios-2.5/.void_file
@@ -18,3 +22,9 @@ sources/xios-2.5/inc/
 sources/xios-2.5/obj/
 sources/xios-2.5/ppsrc/
 sources/xios-2.5/tools/FCM/
+sources/xios-2.5/bin/
+sources/xios-2.5/etc/
+sources/xios-2.5/fcm_env.ksh
+sources/xios-2.5/fcm_env.sh
+sources/xios-2.5/lib/
+sources/ifs-36r4/bin/ifsmaster-ecconf

sources/ifs-36r4/Makefile.d/Makefile.config.ecconf

@@ -54,7 +54,7 @@ FFLAGS                  := -fixed -O2 -fp-model precise -march=core-avx2 -r8
 FPPDEFS                 := $(addprefix -D,linux LINUX LITTLE LITTLE_ENDIAN POINTER_64 BLAS ECCODES)
 
 CC                      := mpicc
-CFLAGS                  := -O2 -fp-model precise -march=core-avx2
+CFLAGS                  := -std=gnu90 -O2 -fp-model precise -march=core-avx2
 CPPDEFS                 := $(addprefix -D,linux LINUX LITTLE LITTLE_ENDIAN POINTER_64 BLAS ECCODES)
 
 LD                      := $(F90)