Add 3.15.6 example app (for compilation tests)

exampleApp/src/exampleHello.c

@@ -0,0 +1,31 @@
+/* Example showing how to register a new command with iocsh */
+
+#include <stdio.h>
+
+#include <epicsExport.h>
+#include <iocsh.h>
+
+/* This is the command, which the vxWorks shell will call directly */
+void hello(const char *name) {
+    if (name) {
+	printf("Hello %s, from example\n", name);
+    } else {
+	puts("Hello from example");
+    }
+}
+
+/* Information needed by iocsh */
+static const iocshArg     helloArg0 = {"name", iocshArgString};
+static const iocshArg    *helloArgs[] = {&helloArg0};
+static const iocshFuncDef helloFuncDef = {"hello", 1, helloArgs};
+
+/* Wrapper called by iocsh, selects the argument types that hello needs */
+static void helloCallFunc(const iocshArgBuf *args) {
+    hello(args[0].sval);
+}
+
+/* Registration routine, runs at startup */
+static void helloRegister(void) {
+    iocshRegister(&helloFuncDef, helloCallFunc);
+}
+epicsExportRegistrar(helloRegister);