Add 3.15.6 example app (for compilation tests)

Makefile

@@ -0,0 +1,31 @@
+# Makefile at top of application tree
+TOP = .
+include $(TOP)/configure/CONFIG
+
+# Directories to build, any order
+DIRS += configure
+DIRS += $(wildcard *Sup)
+DIRS += $(wildcard *App)
+DIRS += $(wildcard *Top)
+DIRS += $(wildcard iocBoot)
+
+# The build order is controlled by these dependency rules:
+
+# All dirs except configure depend on configure
+$(foreach dir, $(filter-out configure, $(DIRS)), \
+    $(eval $(dir)_DEPEND_DIRS += configure))
+
+# Any *App dirs depend on all *Sup dirs
+$(foreach dir, $(filter %App, $(DIRS)), \
+    $(eval $(dir)_DEPEND_DIRS += $(filter %Sup, $(DIRS))))
+
+# Any *Top dirs depend on all *Sup and *App dirs
+$(foreach dir, $(filter %Top, $(DIRS)), \
+    $(eval $(dir)_DEPEND_DIRS += $(filter %Sup %App, $(DIRS))))
+
+# iocBoot depends on all *App dirs
+iocBoot_DEPEND_DIRS += $(filter %App,$(DIRS))
+
+# Add any additional dependency rules here:
+
+include $(TOP)/configure/RULES_TOP