Reoptimize LUT-based Sigmoid evaluation stubs

Recalculate tables to remove masking of extracted exponent bits

PiperOrigin-RevId: 333661363
diff --git a/BUILD.bazel b/BUILD.bazel
index 75d0737..845da5a 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -110,6 +110,8 @@
 TABLE_SRCS = [
     "src/tables/exp2-k-over-64.c",
     "src/tables/exp2-k-over-2048.c",
+    "src/tables/exp2minus-k-over-64.c",
+    "src/tables/exp2minus-k-over-2048.c",
 ]
 
 SCALAR_UKERNELS = [