mesa compile fixes for Clang / VS2013

src/gallium/auxiliary/util/u_math.h

 /**************************************************************************
  * 
  * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
  * All Rights Reserved.
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the
  * "Software"), to deal in the Software without restriction, including
  * without limitation the rights to use, copy, modify, merge, publish,
  * distribute, sub license, and/or sell copies of the Software, and to
@@ skipping 94 matching lines @@
    return (float) log( (double) f );
 }
 
 #else
 /* Work-around an extra semi-colon in VS 2005 logf definition */
 #ifdef logf
 #undef logf
 #define logf(x) ((float)log((double)(x)))
 #endif /* logf */
 
+#if _MSC_VER < 1800
 #define isfinite(x) _finite((double)(x))
 #define isnan(x) _isnan((double)(x))
+#endif /* _MSC_VER < 1800 */
 #endif /* _MSC_VER < 1400 && !defined(__cplusplus) */
 
+#if _MSC_VER < 1800
 static INLINE double log2( double x )
 {
    const double invln2 = 1.442695041;
    return log( x ) * invln2;
 }
 
 static INLINE double
 round(double x)
 {
    return x >= 0.0 ? floor(x + 0.5) : ceil(x - 0.5);
 }
 
 static INLINE float
 roundf(float x)
 {
    return x >= 0.0f ? floorf(x + 0.5f) : ceilf(x - 0.5f);
 }
+#endif
 
 #endif /* _MSC_VER */
 
 
 #ifdef PIPE_OS_ANDROID
 
 static INLINE
 double log2(double d)
 {
    return log(d) * (1.0 / M_LN2);
@@ skipping 615 matching lines @@
    return (int32_t)(value * (1<<frac_bits));
 }
 
 
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif /* U_MATH_H */