Fixed some GCC compiler warnings

modules/juce_box2d/juce_box2d.cpp

@@ -33,10 +33,14 @@
  #error "Incorrect use of JUCE cpp file"
 #endif
 
-#ifdef __clang__
+#if defined (__clang__)
  #pragma clang diagnostic push
  #pragma clang diagnostic ignored "-Wsign-conversion"
  #pragma clang diagnostic ignored "-Wfloat-conversion"
+#elif defined (__GNUC__)
+ #pragma GCC diagnostic push
+ #pragma GCC diagnostic ignored "-Wunused-but-set-variable"
+ #pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
 #endif
 
 #include "juce_box2d.h"
@@ -89,6 +93,8 @@
 
 #include "utils/juce_Box2DRenderer.cpp"
 
-#if JUCE_CLANG
+#if defined (__clang__)
  #pragma clang diagnostic pop
+#elif defined (__GNUC__)
+ #pragma GCC diagnostic pop
 #endif

modules/juce_box2d/juce_box2d.h

@@ -54,14 +54,14 @@
 //==============================================================================
 #include <juce_graphics/juce_graphics.h>
 
-#if __GNUC__
+#ifdef __GNUC__
  #pragma GCC diagnostic push
  #pragma GCC diagnostic ignored "-Wconversion"
 #endif
 
 #include "box2d/Box2D.h"
 
-#if __GNUC__
+#ifdef __GNUC__
  #pragma GCC diagnostic pop
 #endif