Added compiler support detection for variadic templates

modules/juce_core/system/juce_CompilerSupport.h

@@ -41,6 +41,7 @@
  #define JUCE_COMPILER_SUPPORTS_NULLPTR 1
  #define JUCE_COMPILER_SUPPORTS_MOVE_SEMANTICS 1
  #define JUCE_COMPILER_SUPPORTS_INITIALIZER_LISTS 1
+ #define JUCE_COMPILER_SUPPORTS_VARIADIC_TEMPLATES 1
 
  #if (__GNUC__ * 100 + __GNUC_MINOR__) >= 407 && ! defined (JUCE_COMPILER_SUPPORTS_OVERRIDE_AND_FINAL)
   #define JUCE_COMPILER_SUPPORTS_OVERRIDE_AND_FINAL 1
@@ -82,6 +83,10 @@
   #define JUCE_COMPILER_SUPPORTS_INITIALIZER_LISTS 1
  #endif
 
+ #if __has_feature (cxx_variadic_templates)
+  #define JUCE_COMPILER_SUPPORTS_VARIADIC_TEMPLATES 1
+ #endif
+
  #ifndef JUCE_COMPILER_SUPPORTS_OVERRIDE_AND_FINAL
   #define JUCE_COMPILER_SUPPORTS_OVERRIDE_AND_FINAL 1
  #endif
@@ -107,6 +112,7 @@
 
  #if _MSC_VER >= 1800
   #define JUCE_COMPILER_SUPPORTS_INITIALIZER_LISTS 1
+  #define JUCE_COMPILER_SUPPORTS_VARIADIC_TEMPLATES 1
  #endif
 
  #if _MSC_VER >= 1900