engine: common: set Host_Error and Sys_Error as NORETURN

engine/common/common.h

@@ -699,7 +699,7 @@ void Host_WriteConfig( void );
 qboolean Host_IsLocalGame( void );
 qboolean Host_IsLocalClient( void );
 void Host_ShutdownServer( void );
-void Host_Error( const char *error, ... ) _format( 1 );
+void Host_Error( const char *error, ... ) _format( 1 ) NORETURN;
 void Host_PrintEngineFeatures( void );
 void Host_Frame( float time );
 void Host_InitDecals( void );

engine/common/system.h

@@ -51,7 +51,7 @@ char *Sys_GetClipboardData( void );
 const char *Sys_GetCurrentUser( void );
 int Sys_CheckParm( const char *parm );
 void Sys_Warn( const char *format, ... ) _format( 1 );
-void Sys_Error( const char *error, ... ) _format( 1 );
+void Sys_Error( const char *error, ... ) _format( 1 ) NORETURN;
 qboolean Sys_LoadLibrary( dll_info_t *dll );
 void* Sys_GetProcAddress( dll_info_t *dll, const char* name );
 qboolean Sys_FreeLibrary( dll_info_t *dll );