Cycles: fix crash rendering textured objects in OpenCL

Issue was caused by changed order of texture slots -- float textures
have got lower slots indices than byte textures. OpenCL was still assuming
byte textures goes before float.

intern/cycles/kernel/svm/svm_image.h

@@ -52,6 +52,12 @@ __device_inline float svm_image_texture_frac(float x, int *ix)
 
 __device float4 svm_image_texture(KernelGlobals *kg, int id, float x, float y, uint srgb)
 {
+	/* first slots are used by float textures, which are not supported here */
+	if(id < TEX_NUM_FLOAT_IMAGES)
+		return make_float4(1.0f, 0.0f, 1.0f, 1.0f);
+
+	id -= TEX_NUM_FLOAT_IMAGES;
+
 	uint4 info = kernel_tex_fetch(__tex_image_packed_info, id);
 	uint width = info.x;
 	uint height = info.y;