Merge commit '8e234615'

* commit '8e234615':
  libavutil: Hook up the rest of the gcc specific attributes to clang as well

Merged-by: James Almer <jamrial@gmail.com>

libavutil/attributes.h

@@ -66,19 +66,19 @@
 #    define av_noinline
 #endif
 
-#if AV_GCC_VERSION_AT_LEAST(3,1)
+#if AV_GCC_VERSION_AT_LEAST(3,1) || defined(__clang__)
 #    define av_pure __attribute__((pure))
 #else
 #    define av_pure
 #endif
 
-#if AV_GCC_VERSION_AT_LEAST(2,6)
+#if AV_GCC_VERSION_AT_LEAST(2,6) || defined(__clang__)
 #    define av_const __attribute__((const))
 #else
 #    define av_const
 #endif
 
-#if AV_GCC_VERSION_AT_LEAST(4,3)
+#if AV_GCC_VERSION_AT_LEAST(4,3) || defined(__clang__)
 #    define av_cold __attribute__((cold))
 #else
 #    define av_cold
@@ -138,19 +138,19 @@
 #    define av_used
 #endif
 
-#if AV_GCC_VERSION_AT_LEAST(3,3)
+#if AV_GCC_VERSION_AT_LEAST(3,3) || defined(__clang__)
 #   define av_alias __attribute__((may_alias))
 #else
 #   define av_alias
 #endif
 
-#if defined(__GNUC__) && !defined(__INTEL_COMPILER) && !defined(__clang__)
+#if (defined(__GNUC__) || defined(__clang__)) && !defined(__INTEL_COMPILER)
 #    define av_uninit(x) x=x
 #else
 #    define av_uninit(x) x
 #endif
 
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__clang__)
 #    define av_builtin_constant_p __builtin_constant_p
 #    define av_printf_format(fmtpos, attrpos) __attribute__((__format__(__printf__, fmtpos, attrpos)))
 #else