Fix macOS build in C++98 mode

Signed-off-by: falkTX <falktx@falktx.com>

distrho/DistrhoUtils.hpp

@@ -38,7 +38,7 @@
 typedef SSIZE_T ssize_t;
 #endif
 
-#if ! defined(CARLA_MATH_UTILS_HPP_INCLUDED) && ! defined(DISTRHO_PROPER_CPP11_SUPPORT)
+#if ! defined(CARLA_MATH_UTILS_HPP_INCLUDED) && ! defined(DISTRHO_PROPER_CPP11_SUPPORT) && ! defined(DISTRHO_OS_MAC)
 namespace std {
 inline float fmin(float __x, float __y)
   { return __builtin_fminf(__x, __y); }

distrho/src/DistrhoPluginAU.cpp

@@ -119,7 +119,8 @@ static const char* AudioUnitPropertyID2Str(const AudioUnitPropertyID prop) noexc
     PROP(kMusicDeviceProperty_DualSchedulingMode)
     #undef PROP
     // DPF specific properties
-    #define PROP(s) case d_cconst(#s): return #s;
+    #define PROPX(s) (s[0] << 24) | (s[1] << 16) | (s[2] << 8) | (s[3] << 0)
+    #define PROP(s) case PROPX(#s): return #s;
     PROP(DPFi)
     PROP(DPFe)
     PROP(DPFp)
@@ -129,6 +130,7 @@ static const char* AudioUnitPropertyID2Str(const AudioUnitPropertyID prop) noexc
     PROP(DPFs)
     PROP(DPFa)
     #undef PROP
+    #undef PROPX
     }
     return "[unknown]";
 }

distrho/src/DistrhoPluginVST.hpp

@@ -45,7 +45,7 @@
 
 // --------------------------------------------------------------------------------------------------------------------
 
-#ifdef DISTRHO_PROPER_CPP11_SUPPORT
+#if defined(DISTRHO_PROPER_CPP11_SUPPORT) || defined(DISTRHO_OS_MAC)
 # include <atomic>
 #else
 // quick and dirty std::atomic replacement for the things we need

distrho/src/jackbridge/NativeBridge.hpp

@@ -49,10 +49,10 @@ struct NativeBridge {
     uint numMidiOuts;
 
     // JACK callbacks
-    JackProcessCallback jackProcessCallback = nullptr;
-    JackBufferSizeCallback bufferSizeCallback = nullptr;
-    void* jackProcessArg = nullptr;
-    void* jackBufferSizeArg = nullptr;
+    JackProcessCallback jackProcessCallback;
+    JackBufferSizeCallback bufferSizeCallback;
+    void* jackProcessArg;
+    void* jackBufferSizeArg;
 
     // Runtime buffers
     enum PortMask {