Fix some clang/LLVM warnings

src/86box.c

@@ -97,6 +97,13 @@
 #include <86box/version.h>
 #include <86box/gdbstub.h>
 
+// Disable c99-designator to avoid the warnings about int ng
+#ifdef __clang__
+#if __has_warning("-Wunused-but-set-variable")
+#pragma clang diagnostic ignored "-Wunused-but-set-variable"
+#endif
+#endif
+
 
 /* Stuff that used to be globally declared in plat.h but is now extern there
    and declared here instead. */

src/discord.c

@@ -89,7 +89,9 @@ discord_update_activity(int paused)
 	*(paren - 1) = '\0';
 
 #pragma GCC diagnostic push
+#if defined(__GNUC__)
 #pragma GCC diagnostic ignored "-Wformat-truncation"
+#endif
     if (strlen(vm_name) < 100)
     {
 	snprintf(activity.details, sizeof(activity.details), "Running \"%s\"", vm_name);

src/sound/midi_rtmidi.cpp

@@ -36,6 +36,13 @@ extern "C"
 #include <86box/midi_rtmidi.h>
 #include <86box/config.h>
 
+// Disable c99-designator to avoid the warnings in rtmidi_*_device
+#ifdef __clang__
+#if __has_warning("-Wc99-designator")
+#pragma clang diagnostic ignored "-Wc99-designator"
+#endif
+#endif
+
 static RtMidiOut *  midiout = nullptr;
 static RtMidiIn *   midiin = nullptr;
 static int          midi_out_id = 0, midi_in_id = 0;