WAsm SIMD version of X32 PAD microkernel

PiperOrigin-RevId: 321662844
diff --git a/BUILD.bazel b/BUILD.bazel
index ad472db..3187399 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -802,6 +802,7 @@
     "src/f32-vunary/gen/vsqr-wasmsimd-x8.c",
     "src/x32-fill/wasmsimd.c",
     "src/x32-packx/x4-wasmsimd.c",
+    "src/x32-pad/wasmsimd.c",
     "src/math/roundne-wasmsimd-addsub.c",
     "src/math/roundd-wasmsimd-addsub.c",
     "src/math/roundd-wasmsimd-cvt.c",