Fixed GDTR singleton (http://stackoverflow.com/questions/22985570)

libuavcan/include/uavcan/node/global_data_type_registry.hpp

@@ -60,6 +60,12 @@ private:
     mutable List srvs_;
     bool frozen_;
 
+    /**
+     * We can't use function local static variable for singleton because of code size issues:
+     *     http://stackoverflow.com/questions/22985570
+     */
+    static GlobalDataTypeRegistry singleton;
+
     GlobalDataTypeRegistry() : frozen_(false) { }
 
     List* selectList(DataTypeKind kind) const;

libuavcan/src/node/uc_global_data_type_registry.cpp

@@ -10,6 +10,8 @@
 namespace uavcan
 {
 
+GlobalDataTypeRegistry GlobalDataTypeRegistry::singleton;
+
 GlobalDataTypeRegistry::List* GlobalDataTypeRegistry::selectList(DataTypeKind kind) const
 {
     if (kind == DataTypeKindMessage)
@@ -115,8 +117,7 @@ GlobalDataTypeRegistry::RegistResult GlobalDataTypeRegistry::registImpl(Entry* d
 
 GlobalDataTypeRegistry& GlobalDataTypeRegistry::instance()
 {
-    static GlobalDataTypeRegistry inst;
-    return inst;
+    return singleton;
 }
 
 void GlobalDataTypeRegistry::freeze()