add debug info for function parameter types

gen/dibuilder.cpp

@@ -725,11 +725,12 @@ DISubroutineType DIBuilder::CreateFunctionType(Type *type) {
   assert(t);
 
   Type *retType = t->next;
-
-  // Create "dummy" subroutine type for the return type
-  LLMetadata *params = {CreateTypeDescription(retType)};
+  llvm::SmallVector<LLMetadata *, 8> params;
+  params.emplace_back(CreateTypeDescription(retType));
+  if (auto parameters = t->parameterList.parameters)
+    for (auto &p : *parameters)
+      params.emplace_back(CreateTypeDescription(p->type));
   auto paramsArray = DBuilder.getOrCreateTypeArray(params);
-
   return DBuilder.createSubroutineType(paramsArray, DIFlags::FlagZero, 0);
 }
 
@@ -809,6 +810,8 @@ DIType DIBuilder::CreateTypeDescription(Type *t, bool voidToUbyte) {
     return CreateFunctionType(tf);
   if (auto td = t->isTypeDelegate())
     return CreateDelegateType(td);
+  if (auto tt = t->isTypeTuple())
+    return DBuilder.createUnspecifiedType(processDIName("tuple")); // TODO
 
   // Crash if the type is not supported.
   llvm_unreachable("Unsupported type in debug info");