Evaluation stubs for gather-based AVX2/AVX512 Sigmoid

PiperOrigin-RevId: 337414295
diff --git a/BUILD.bazel b/BUILD.bazel
index ea33a2b..b3044bc 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -2489,6 +2489,14 @@
     "src/math/sigmoid-avx2-rr2-p5-nr2fma.c",
     "src/math/sigmoid-avx2-rr1-p5-nr1fma.c",
     "src/math/sigmoid-avx2-rr2-p5-nr1fma.c",
+    "src/math/sigmoid-avx2-rr1-lut64-p2-gather-div.c",
+    "src/math/sigmoid-avx2-rr2-lut64-p2-gather-div.c",
+    "src/math/sigmoid-avx2-rr1-lut64-p2-gather-nr2fma1adj.c",
+    "src/math/sigmoid-avx2-rr2-lut64-p2-gather-nr2fma1adj.c",
+    "src/math/sigmoid-avx2-rr1-lut64-p2-gather-nr2fma.c",
+    "src/math/sigmoid-avx2-rr2-lut64-p2-gather-nr2fma.c",
+    "src/math/sigmoid-avx2-rr1-lut64-p2-gather-nr1fma.c",
+    "src/math/sigmoid-avx2-rr2-lut64-p2-gather-nr1fma.c",
 ]
 
 AVX512F_UKERNELS = [
@@ -2721,6 +2729,12 @@
     "src/math/sigmoid-avx512f-rr2-lut32-p2-perm2-scalef-div.c",
     "src/math/sigmoid-avx512f-rr2-lut32-p2-perm2-scalef-nr1fma1adj.c",
     "src/math/sigmoid-avx512f-rr2-lut32-p2-perm2-scalef-nr1fma.c",
+    "src/math/sigmoid-avx512f-rr1-lut64-p2-gather-scalef-div.c",
+    "src/math/sigmoid-avx512f-rr1-lut64-p2-gather-scalef-nr1fma1adj.c",
+    "src/math/sigmoid-avx512f-rr1-lut64-p2-gather-scalef-nr1fma.c",
+    "src/math/sigmoid-avx512f-rr2-lut64-p2-gather-scalef-div.c",
+    "src/math/sigmoid-avx512f-rr2-lut64-p2-gather-scalef-nr1fma1adj.c",
+    "src/math/sigmoid-avx512f-rr2-lut64-p2-gather-scalef-nr1fma.c",
     "src/math/sqrt-avx512f-nr1fma.c",
     "src/math/sqrt-avx512f-nr2fma.c",
     "src/math/sqrt-avx512f-nr1fma1adj.c",