extract out a caffe2 macros library (#98156)

Slowly carving out the minimal caffe2 dependencies to build PyTorch.

Differential Revision: [D44609764](https://our.internmc.facebook.com/intern/diff/D44609764/)

**NOTE FOR REVIEWERS**: This PR has internal Meta-specific changes or comments, please review them on [Phabricator](https://our.internmc.facebook.com/intern/diff/D44609764/)!
Pull Request resolved: https://github.com/pytorch/pytorch/pull/98156
Approved by: https://github.com/ezyang, https://github.com/PaliC

BUILD.bazel

@@ -1261,7 +1261,7 @@ cc_library(
     copts = CAFFE2_COPTS,
     visibility = ["//visibility:public"],
     deps = [
-        ":caffe2_core_macros_h",
+        ":caffe2_core_macros",
         "//c10:headers",
         "//caffe2/proto:caffe2_pb",
     ],
@@ -1292,7 +1292,8 @@ genrule(
 
 cc_library(
     name = "caffe2_headers",
-    hdrs = glob([
+    hdrs = glob(
+        [
             "caffe2/contrib/aten/*.h",
             "caffe2/contrib/gloo/*.h",
             "caffe2/core/*.h",
@@ -1326,7 +1327,11 @@ cc_library(
             "caffe2/utils/math/*.h",
             "caffe2/utils/threadpool/*.h",
             "modules/**/*.h",
-    ]) + if_cuda(glob([
+        ],
+        exclude = [
+            "caffe2/core/macros.h",
+        ],
+    ) + if_cuda(glob([
         "caffe2/**/*.cuh",
         "caffe2/image/*.h",
     ])) + [":generated_caffe2_aten_op_headers"],
@@ -1337,6 +1342,7 @@ cc_library(
     ],
     visibility = ["//visibility:public"],
     deps = [
+        ":caffe2_core_macros",
         ":caffe2_for_aten_headers",
         "//caffe2/proto:caffe2_pb",
         "//caffe2/proto:cc_proto",
@@ -1395,6 +1401,7 @@ cc_library(
     linkstatic = 1,
     visibility = ["//visibility:public"],
     deps = [
+        ":caffe2_core_macros",
         ":caffe2_dnnlowp_avx2_ops",
         ":caffe2_headers",
         ":caffe2_perfkernels_avx",

build.bzl

@@ -6,6 +6,11 @@ load(
 )
 
 def define_targets(rules):
+    rules.cc_library(
+        name = "caffe2_core_macros",
+        hdrs = [":caffe2_core_macros_h"],
+    )
+
     rules.cmake_configure_file(
         name = "caffe2_core_macros_h",
         src = "caffe2/core/macros.h.in",