Don't crash when declaring methods on unknown name.

From-SVN: r168131

gcc/go/gofrontend/gogo.cc

@@ -3710,6 +3710,18 @@ Named_object::set_function_value(Function* function)
   this->u_.func_value = function;
 }
 
+// Declare an unknown object as a type declaration.
+
+void
+Named_object::declare_as_type()
+{
+  gcc_assert(this->classification_ == NAMED_OBJECT_UNKNOWN);
+  Unknown_name* unk = this->u_.unknown_value;
+  this->classification_ = NAMED_OBJECT_TYPE_DECLARATION;
+  this->u_.type_declaration = new Type_declaration(unk->location());
+  delete unk;
+}
+
 // Return the location of a named object.
 
 source_location

gcc/go/gofrontend/gogo.h

@@ -1815,6 +1815,10 @@ class Named_object
   void
   set_function_value(Function*);
 
+  // Declare an unknown name as a type declaration.
+  void
+  declare_as_type();
+
   // Export this object.
   void
   export_named_object(Export*) const;

gcc/go/gofrontend/types.cc

@@ -8013,7 +8013,8 @@ Forward_declaration_type::add_method(const std::string& name,
 				     Function* function)
 {
   Named_object* no = this->named_object();
-  gcc_assert(no->is_type_declaration());
+  if (no->is_unknown())
+    no->declare_as_type();
   return no->type_declaration_value()->add_method(name, function);
 }
 
@@ -8026,7 +8027,8 @@ Forward_declaration_type::add_method_declaration(const std::string& name,
 						 source_location location)
 {
   Named_object* no = this->named_object();
-  gcc_assert(no->is_type_declaration());
+  if (no->is_unknown())
+    no->declare_as_type();
   Type_declaration* td = no->type_declaration_value();
   return td->add_method_declaration(name, type, location);
 }