AVX versions of Sigmoid evaluation stubs

PiperOrigin-RevId: 333461551
diff --git a/BUILD.bazel b/BUILD.bazel
index cd2b2e2..b85024e 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -2225,6 +2225,8 @@
     "src/f32-vunary/gen/vsqr-avx-x8.c",
     "src/f32-vunary/gen/vsqr-avx-x16.c",
     "src/math/exp-avx-p5.c",
+    "src/math/sigmoid-avx-rr2-p5-div.c",
+    "src/math/sigmoid-avx-rr2-lut64-p2-div.c",
 ]
 
 XOP_UKERNELS = [