Setting large code model for kernel RTS on 64 bits architectures.

The large code model which is now the default for kernel RTS
(not triggered by the large multilib anymore) on 64 bits
architectures.

TN: UB03-045
Tested-with: $ anod test cross-testsuite \
   --target=x86_64-vx7r2,7.2,vxsim-64 \
   --qualifier=rts=kernel
   $ anod test cross-testsuite \
   --target=aarch64-vx7r2,7.2,vxsim-64 \
   --qualifier=rts=kernel
   $ anod test cross-testsuite \
   --target=ppc64-vx7r2,7.2,vxsim-64 \
   --qualifier=rts=kernel

Makefile

@@ -27,10 +27,22 @@ CONF_ARGS = $(TARGET_CONF) $(RTS_CONF)
 GPROPTS = $(CONF_ARGS) -XAUNIT_BUILD_MODE=$(MODE) -XAUNIT_RUNTIME=$(RTS) \
 		-XAUNIT_PLATFORM=$(TARGET)
 
+# For the 64 bits architectures, the large code model has to be used.
+# with rtp-large, gprconfig ensures that -mcmodel=large is used,
+# but it is managed here for the default (kernel).
+GPROPTS_EXTRA=
+ifneq ($(strip $(filter aarch64-wrs-vxworks7r2 powerpc64-wrs-vxworks7r2 x86_64-wrs-vxworks7r2,$(TARGET))),)
+ifeq (${RTS_CONF},)
+# This covers the kernel RTS because for rtp, the RTS_OPT variable is defined to --RTS=rtp.
+# kernel is the default and the RTS_OPT is not set in that case.
+GPROPTS_EXTRA+=-cargs -mcmodel=large -largs -mcmodel=large
+endif
+endif
+
 .PHONY: all clean targets install_clean install
 
 all:
-	$(GPRBUILD) -p $(GPROPTS) lib/gnat/aunit.gpr
+	$(GPRBUILD) -p $(GPROPTS) lib/gnat/aunit.gpr ${GPROPTS_EXTRA}
 
 clean-lib:
 	$(RM) -fr lib/aunit lib/aunit-obj