Add functions w/ pointer return types

grammar.coffee

@@ -69,7 +69,7 @@ module.exports = grammar
 
     function_declaration: -> seq(
       @type,
-      @identifier,
+      @type_expression,
       "(", @formal_parameters, ")",
       choice(";", @statement_block))
 

grammar_test/declarations.txt

@@ -141,7 +141,7 @@ int main(int argc, const char **argv);
 Function definitions
 ============================================
 
-void do_stuff(int arg1) {
+void * do_stuff(int arg1) {
   return 5;
 }
 
@@ -149,6 +149,6 @@ void do_stuff(int arg1) {
 
 (function_declaration
   (identifier)
-  (identifier)
+  (pointer_type (identifier))
   (field (identifier) (identifier))
   (statement_block (return_statement (number))))