Merge pull request #448 from gmlueck/gmlueck/vec-align

Limit vec alignment to 64 bytes

(cherry picked from commit 472b3a2)

adoc/chapters/programming_interface.adoc

@@ -17670,6 +17670,15 @@ This is true for both host and device code in order to allow for instances
 of the [code]#vec# class template to be passed to SYCL kernel
 functions.
 
+In no case, however, is the alignment guaranteed to be greater than 64 bytes.
+
+[NOTE]
+====
+The alignment guarantee is limited to 64 bytes because some host compilers
+(e.g. on Microsoft Windows) limit the maximum alignment of function parameters
+to this value.
+====
+
 
 ==== Performance note