eal/x86: rework some vector constant for MSVC

MSVC __declspec(align(#)) is limited and accepts only integer literals
as opposed to constant expressions. Define XMM_SIZE to be 16 instead of
sizeof(xmm_t) and static_assert that sizeof(xmm_t) == 16 for
compatibility.

Signed-off-by: Tyler Retzlaff <[email protected]>
Acked-by: Morten Brørup <[email protected]>
Acked-by: Konstantin Ananyev <[email protected]>

Author: Tyler Retzlaff

lib/eal/x86/include/rte_vect.h

@@ -11,6 +11,7 @@
  * RTE SSE/AVX related header.
  */
 
+#include <assert.h>
 #include <stdint.h>
 #include <rte_config.h>
 #include <rte_common.h>
@@ -33,9 +34,11 @@ extern "C" {
 
 typedef __m128i xmm_t;
 
-#define	XMM_SIZE	(sizeof(xmm_t))
+#define	XMM_SIZE	16
 #define	XMM_MASK	(XMM_SIZE - 1)
 
+static_assert(sizeof(xmm_t) == XMM_SIZE, "");
+
 typedef union rte_xmm {
 	xmm_t    x;
 	uint8_t  u8[XMM_SIZE / sizeof(uint8_t)];