[OE-core] [PATCH] local.conf.sample.extended: Add an example of how to enable fortran

[Richard Purdie]

Add an example of how to enable FORTRAN from local.conf. Make
it clear this is not officially supported.

[YOCTO #5091]

Signed-off-by: Richard Purdie <richard.purdie at linuxfoundation.org>

--- a/meta/conf/local.conf.sample.extended
+++ b/meta/conf/local.conf.sample.extended
@@ -229,3 +229,11 @@
 #groupmod -g 1020 developers; \
 #usermod -s /bin/sh tester; \
 #"
+
+# Enabling FORTRAN
+# Note this is not officially supported and is just illustrated here to
+# show an example of how it can be done
+FORTRAN_forcevariable = ",fortran"
+RUNTIMETARGET_append_pn-gcc-runtime = " libquadmath libgfortran"
+export BUILD_FC = "${CCACHE}${BUILD_PREFIX}gfortran ${BUILD_CC_ARCH}"
+export FC = "${CCACHE}${HOST_PREFIX}gfortran ${HOST_CC_ARCH}"