Add bootstrap kernel

This is not a compliant kernel at all, no ABI3, etc. Just an initial
upload so that we can start with support in `kernels`.

build/torch27-cxx98-metal-arm64-darwin/relu/_C.cpython-312-darwin.so

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c8802bc414cef1e69ac716bd0d5c10af715c1a07c7d6b1de093a7b6e1e4a8f59
+size 96216

build/torch27-cxx98-metal-arm64-darwin/relu/__init__.py

@@ -0,0 +1,7 @@
+import torch
+
+from . import _C
+
+
+def relu(input: torch.Tensor) -> torch.Tensor:
+    return torch.ops._C.relu(input)