added extern C on epicsExportRegistrar

exampleDatabase/src/exampleMonitorPluginRegister.cpp

@@ -58,4 +58,7 @@ std::cout << "exampleMonitorPluginRegister\n";
     }
 std::cout << "exampleMonitorPluginRegister returning\n";
 }
+
+extern "C" {
     epicsExportRegistrar(exampleMonitorPluginRegister);
+}

exampleLink/src/exampleLinkRegister.cpp

@@ -83,4 +83,7 @@ static void exampleLinkRegister(void)
         iocshRegister(&exampleLinkFuncDef, exampleLinkCallFunc);
     }
 }
+
+extern "C" {
     epicsExportRegistrar(exampleLinkRegister);
+}

exampleServer/src/exampleServerRegister.cpp

@@ -64,4 +64,7 @@ static void exampleServerRegister(void)
         iocshRegister(&exampleServerFuncDef, exampleServerCallFunc);
     }
 }
+
+extern "C" {
     epicsExportRegistrar(exampleServerRegister);
+}

test/src/powerSupplyRegister.cpp

@@ -66,4 +66,7 @@ static void powerSupplyRegister(void)
         iocshRegister(&powerSupplyFuncDef, powerSupplyCallFunc);
     }
 }
+
+extern "C" {
     epicsExportRegistrar(powerSupplyRegister);
+}