Fixed compilation on mingw.

include/private/SkTLogic.h

Index: include/private/SkTLogic.h
diff --git a/include/private/SkTLogic.h b/include/private/SkTLogic.h
index 49fd6c1c7bd08394e2b46bf6e4c28e339143d542..bf33a0305f4836b611f40201a0e265c24bf91462 100644
--- a/include/private/SkTLogic.h
+++ b/include/private/SkTLogic.h
@@ -49,14 +49,16 @@ template <typename R, typename... Args> struct is_function<R(Args...)> : std::tr
 template <typename R, typename... Args> struct is_function<R __cdecl (Args...)> : std::true_type {};
 template <typename R, typename... Args> struct is_function<R __stdcall (Args...)> : std::true_type {};
 template <typename R, typename... Args> struct is_function<R __fastcall (Args...)> : std::true_type {};
-#if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2
+#if defined(_MSC_VER) && SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2
 template <typename R, typename... Args> struct is_function<R __vectorcall (Args...)> : std::true_type {};
 #endif
 #else
 template <typename R, typename... Args> struct is_function<R __cdecl (Args...)> : std::true_type {};
+#if defined(_MSC_VER)
 template <typename R, typename... Args> struct is_function<R __vectorcall (Args...)> : std::true_type {};
 #endif
 #endif
+#endif

[bungeman-skia, 2016/01/14 18:04:58]

I would really like to avoid another nesting ifdef here, it's getting hard to
read. This was originally structured on the idea that it would be clearer to
have each individual platform (or set of calling conventions) in one block. As
it turns out, this is a bit of a mess. I think it's clearer to restructure this,
replacing the above lines 48 to 60 with

template <typename R, typename... Args> struct is_function<R __cdecl (Args...)>
: std::true_type {};
#  if defined(_M_IX86)
template <typename R, typename... Args> struct is_function<R __stdcall
(Args...)> : std::true_type {};
template <typename R, typename... Args> struct is_function<R __fastcall
(Args...)> : std::true_type {};
#  endif
#  if defined(_MSC_VER) && (SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2)
template <typename R, typename... Args> struct is_function<R __vectorcall
(Args...)> : std::true_type {};
#  endif

 template <typename R, typename... Args> struct is_function<R(Args..., ...)> : std::true_type {};
 
 template <typename T> using add_const_t = typename std::add_const<T>::type;