[bazel] Add support for building orc_rt (#87730)

Author: keith

utils/bazel/llvm-project-overlay/compiler-rt/BUILD.bazel

@@ -54,3 +54,57 @@ cc_library(
         ":config",
     ],
 )
+
+cc_library(
+    name = "orc_rt_common_headers",
+    hdrs = [
+        "lib/orc/adt.h",
+        "lib/orc/bitmask_enum.h",
+        "lib/orc/common.h",
+        "lib/orc/compiler.h",
+        "lib/orc/debug.h",
+        "lib/orc/endianness.h",
+        "lib/orc/error.h",
+        "lib/orc/executor_address.h",
+        "lib/orc/executor_symbol_def.h",
+        "lib/orc/extensible_rtti.h",
+        "lib/orc/interval_map.h",
+        "lib/orc/interval_set.h",
+        "lib/orc/simple_packed_serialization.h",
+        "lib/orc/stl_extras.h",
+        "lib/orc/string_pool.h",
+        "lib/orc/wrapper_function_utils.h",
+    ],
+    strip_include_prefix = "lib/orc",
+)
+
+cc_library(
+    name = "orc_rt",
+    srcs = [
+        "lib/orc/debug.cpp",
+        "lib/orc/dlfcn_wrapper.cpp",
+        "lib/orc/extensible_rtti.cpp",
+        "lib/orc/log_error_to_stderr.cpp",
+        "lib/orc/run_program_wrapper.cpp",
+    ] + select({
+        "@platforms//os:macos": [
+            "lib/orc/macho_platform.cpp",
+            "lib/orc/macho_platform.h",
+            "lib/orc/macho_tlv.arm64.S",
+            "lib/orc/macho_tlv.x86-64.S",
+        ],
+        "@platforms//os:linux": [
+            "lib/orc/elfnix_platform.cpp",
+            "lib/orc/elfnix_platform.h",
+            "lib/orc/elfnix_tls.aarch64.S",
+            "lib/orc/elfnix_tls.ppc64.S",
+            "lib/orc/elfnix_tls.x86-64.S",
+        ],
+    }),
+    hdrs = glob(["include/orc_rt/*.h"]),
+    includes = ["include"],
+    linkstatic = True,
+    deps = [
+        ":orc_rt_common_headers",
+    ],
+)

utils/bazel/llvm-project-overlay/compiler-rt/lib/orc/tests/unit/BUILD.bazel

@@ -0,0 +1,28 @@
+# This file is licensed under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+package(
+    default_visibility = ["//visibility:public"],
+    features = ["layering_check"],
+)
+
+licenses(["notice"])
+
+[
+    cc_test(
+        name = "{}".format(file.split(".")[0]),
+        srcs = [file] + glob(["*.h"]),
+        deps = [
+            "//compiler-rt:orc_rt",
+            "//compiler-rt:orc_rt_common_headers",
+            "//third-party/unittest:gtest",
+            "//third-party/unittest:gtest_main",
+        ],
+    )
+    for file in glob(
+        ["*.cpp"],
+        # TODO: Broken with older libc++ versions, currently unused anyways
+        exclude = ["interval_set_test.cpp"],
+    )
+]