typeCallInternal needs to make sure its args are guarded

It used to get away with telling other functions that it had
already guarded its args, since it could rely on the fact that
it could only get called through the path in runtimeCallInternal
that would guard the args.

Now that it can be called through the tpp_call fastpath (which maybe
should just guard the args), it has to guard them itself.

src/runtime/types.cpp

@@ -606,6 +606,25 @@ static Box* typeCallInner(CallRewriteArgs* rewrite_args, ArgPassSpec argspec, Bo
         // This is probably a duplicate, but it's hard to really convince myself of that.
         // Need to create a clear contract of who guards on what
         r_ccls->addGuard((intptr_t)arg1 /* = _cls */);
+
+
+        if (!rewrite_args->args_guarded) {
+            // TODO should know which args don't need to be guarded, ex if we're guaranteed that they
+            // already fit, either since the type inferencer could determine that,
+            // or because they only need to fit into an UNKNOWN slot.
+
+            if (npassed_args >= 1)
+                rewrite_args->arg1->addAttrGuard(offsetof(Box, cls), (intptr_t)arg1->cls);
+            if (npassed_args >= 2)
+                rewrite_args->arg2->addAttrGuard(offsetof(Box, cls), (intptr_t)arg2->cls);
+            if (npassed_args >= 3)
+                rewrite_args->arg3->addAttrGuard(offsetof(Box, cls), (intptr_t)arg3->cls);
+            for (int i = 3; i < npassed_args; i++) {
+                RewriterVar* v = rewrite_args->args->getAttr((i - 3) * sizeof(Box*), Location::any());
+                v->addAttrGuard(offsetof(Box, cls), (intptr_t)args[i - 3]->cls);
+            }
+            rewrite_args->args_guarded = true;
+        }
     }
 
     if (rewrite_args) {
@@ -723,7 +742,7 @@ static Box* typeCallInner(CallRewriteArgs* rewrite_args, ArgPassSpec argspec, Bo
             r_made = rewrite_args->rewriter->call(true, (void*)objectNewNoArgs, r_ccls);
         } else {
             CallRewriteArgs srewrite_args(rewrite_args->rewriter, r_new, rewrite_args->destination);
-            srewrite_args.args_guarded = true;
+            srewrite_args.args_guarded = rewrite_args->args_guarded;
             srewrite_args.func_guarded = true;
 
             int new_npassed_args = new_argspec.totalPassed();
@@ -786,7 +805,6 @@ static Box* typeCallInner(CallRewriteArgs* rewrite_args, ArgPassSpec argspec, Bo
         if (rewrite_args && init_attr->cls == function_cls) {
             // Note: this code path includes the descriptor logic
             CallRewriteArgs srewrite_args(rewrite_args->rewriter, r_init, rewrite_args->destination);
-            if (npassed_args >= 1)
             srewrite_args.arg1 = r_made;
             if (npassed_args >= 2)
                 srewrite_args.arg2 = rewrite_args->arg2;
@@ -794,7 +812,7 @@ static Box* typeCallInner(CallRewriteArgs* rewrite_args, ArgPassSpec argspec, Bo
                 srewrite_args.arg3 = rewrite_args->arg3;
             if (npassed_args >= 4)
                 srewrite_args.args = rewrite_args->args;
-            srewrite_args.args_guarded = true;
+            srewrite_args.args_guarded = rewrite_args->args_guarded;
             srewrite_args.func_guarded = true;
 
             // initrtn = callattrInternal(cls, _init_str, INST_ONLY, &srewrite_args, argspec, made, arg2, arg3, args,