AK+LibIDL: Put IDL dbgln statement behind a debug flag

This is a bit spammy now that we are performing some overload resolution
at build time. The fallback to an interface has generally worked fine on
the types it warns about (BufferSource, Module, etc.) so let's not warn
about it for every build.

AK/Debug.h.in

@@ -210,6 +210,10 @@
 #    cmakedefine01 ICO_DEBUG
 #endif
 
+#ifndef IDL_DEBUG
+#    cmakedefine01 IDL_DEBUG
+#endif
+
 #ifndef ILBM_DEBUG
 #    cmakedefine01 ILBM_DEBUG
 #endif

Meta/CMake/all_the_debug_macros.cmake

@@ -73,6 +73,7 @@ set(HTTPJOB_DEBUG ON)
 set(HUNKS_DEBUG ON)
 set(ICMP_DEBUG ON)
 set(ICO_DEBUG ON)
+set(IDL_DEBUG ON)
 set(ILBM_DEBUG ON)
 set(IMAGE_DECODER_DEBUG ON)
 set(IMAGE_LOADER_DEBUG ON)

Meta/gn/secondary/AK/BUILD.gn

@@ -288,6 +288,7 @@ write_cmake_config("ak_debug_gen") {
     "HTTPJOB_DEBUG=",
     "HUNKS_DEBUG=",
     "ICO_DEBUG=",
+    "IDL_DEBUG=",
     "ILBM_DEBUG=",
     "IMAGE_DECODER_DEBUG=",
     "IMAGE_LOADER_DEBUG=",

Userland/Libraries/LibIDL/Types.cpp

@@ -5,6 +5,7 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <AK/Debug.h>
 #include <LibIDL/Types.h>
 
 namespace IDL {
@@ -175,7 +176,7 @@ bool Type::is_distinguishable_from(IDL::Interface const& interface, IDL::Type co
             return DistinguishabilityCategory::SequenceLike;
 
         // FIXME: For lack of a better way of determining if something is an interface type, this just assumes anything we don't recognise is one.
-        dbgln("Unable to determine category for type named '{}', assuming it's an interface type.", type.name());
+        dbgln_if(IDL_DEBUG, "Unable to determine category for type named '{}', assuming it's an interface type.", type.name());
         return DistinguishabilityCategory::InterfaceLike;
     };