Resolve unknown parameter type as unknown type (not value)

Author: FnControlOption

src/analysis.zig

@@ -2350,7 +2350,7 @@ fn resolveTypeOfNodeUncached(analyser: *Analyser, node_handle: NodeWithHandle) e
                             else => unreachable,
                         }
                     }
-                    break :param_type Type.fromIP(analyser, InternPool.Index.unknown_type, null);
+                    break :param_type Type.fromIP(analyser, .type_type, .unknown_type);
                 };
 
                 try parameters.append(analyser.arena.allocator(), .{
@@ -2368,7 +2368,7 @@ fn resolveTypeOfNodeUncached(analyser: *Analyser, node_handle: NodeWithHandle) e
                 if (try analyser.resolveReturnTypeInternal(handle, fn_proto)) |ty| {
                     break :blk ty;
                 }
-                return null;
+                break :blk Type.fromIP(analyser, .type_type, .unknown_type);
             };
 
             const info: Type.Data.Function = .{

tests/analysis/function.zig

@@ -0,0 +1,7 @@
+const Unknown: type = undefined;
+
+fn unknown_parameter_type(_: Unknown) void {}
+// ^^^^^^^^^^^^^^^^^^^^^^ (fn ((unknown type)) void)()
+
+fn unknown_return_type() Unknown {}
+// ^^^^^^^^^^^^^^^^^^^ (fn () (unknown type))()