Two small bugfixes:

- See through typedefs and enums in passByVal
 - Don't depend on TypeFunction::parameters->dim being the actual number of
   parameters; it contains unexpanded tuples as single elements.

gen/abi-x86-64.cpp

@@ -563,6 +563,7 @@ bool X86_64TargetABI::returnInArg(TypeFunction* tf) {
 }
 
 bool X86_64TargetABI::passByVal(Type* t) {
+    t = t->toBasetype();
     if (linkage() == LINKd) {
         if (t->ty != Tstruct)
             return false;

gen/functions.cpp

@@ -185,7 +185,7 @@ const llvm::FunctionType* DtoFunctionType(Type* type, Type* thistype, Type* nest
     }
 
     // reverse params?
-    if (f->fty->reverseParams && f->parameters->dim > 1)
+    if (f->fty->reverseParams && nargs2 > 1)
     {
         std::reverse(argtypes.begin() + beg, argtypes.end());
     }