Do not include clc_nextafter header globally

Drop unused clc/math/clc_nextafter.h header

Reviewer: Jeroen Ketema
Signed-off-by: Jan Vesely <jan.vesely@rutgers.edu>
llvm-svn: 315190
diff --git a/libclc/amdgpu/lib/math/nextafter.cl b/libclc/amdgpu/lib/math/nextafter.cl
index 6aee0a0..5b4521d 100644
--- a/libclc/amdgpu/lib/math/nextafter.cl
+++ b/libclc/amdgpu/lib/math/nextafter.cl
@@ -1,5 +1,6 @@
 #include <clc/clc.h>
 #include "../lib/clcmacro.h"
+#include <math/clc_nextafter.h>
 
 _CLC_DEFINE_BINARY_BUILTIN(float, nextafter, __clc_nextafter, float, float)