MSVC: Fix include, fix GNU compiler flag

plugins/OpulenZ/CMakeLists.txt

@@ -1,7 +1,9 @@
 INCLUDE(BuildPlugin)
 
 # Avoid unused warnings for mididata.h
+IF(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
 SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-unused-variable")
+ENDIF()
 
 INCLUDE_DIRECTORIES(adplug/src)
 

src/core/LocklessAllocator.cpp

@@ -26,13 +26,12 @@
 
 #include <stdio.h>
 
+#include "lmmsconfig.h"
+
 #ifndef LMMS_BUILD_WIN32
 #include <strings.h>
 #endif
 
-#include "lmmsconfig.h"
-
-
 static const size_t SIZEOF_SET = sizeof( int ) * 8;