AVX2 version of QS8 GEMM and IGEMM microkernels

PiperOrigin-RevId: 324543693
diff --git a/src/qs8-igemm/gen/2x4c8-minmax-sse2-ld64.c b/src/qs8-igemm/gen/2x4c8-minmax-sse2-ld64.c
index 1d66dc9..becb16b 100644
--- a/src/qs8-igemm/gen/2x4c8-minmax-sse2-ld64.c
+++ b/src/qs8-igemm/gen/2x4c8-minmax-sse2-ld64.c
@@ -32,7 +32,9 @@
   assert(mr <= 2);
   assert(nc != 0);
   assert(kc != 0);
-  assert(kc % sizeof(int8_t) == 0);
+  assert(ks != 0);
+  assert(ks % (2 * sizeof(void*)) == 0);
+  assert(a_offset % sizeof(int8_t) == 0);
   assert(a != NULL);
   assert(w != NULL);
   assert(c != NULL);