Use __FUNCTION__ for MSVC

Author: saper

debug.hpp

@@ -13,7 +13,7 @@ enum dbg_lvl_t : uint32_t {
 	EXTEND_COMPOUND = 16,
 	EXTEND_COMPLEX = 32,
 	LCS = 64,
-  EXTEND_OBJECT = 128,
+	EXTEND_OBJECT = 128,
 	ALL = UINT32_MAX
 };
 
@@ -38,6 +38,11 @@ namespace Sass {
   };
 }
 
+// Visual Studio 2013 does not like __func__
+#if _MSC_VER < 1900
+#define __func__ __FUNCTION__
+#endif
+
 #define TRACE() \
   if (logTRACE > Sass::LibsassLogReportingLevel) ; \
   else Sass::Log().Get(Sass::logTRACE, __func__, __FILE__, __LINE__)