Make tf_gen_op_libs macro more flexible by adding a sub_directory arg.

This is to prepare for moving op targets to a new build file under
tensorflow/core/ops.

PiperOrigin-RevId: 336554704
Change-Id: Ib1d83f78467c5fa6aa800b3d3af7b23374515c8d

tensorflow/tensorflow.bzl

@@ -399,7 +399,12 @@ def tf_defines_nortti_if_lite_protos():
 
 # Given a list of "op_lib_names" (a list of files in the ops directory
 # without their .cc extensions), generate a library for that file.
-def tf_gen_op_libs(op_lib_names, deps = None, is_external = True, compatible_with = None):
+def tf_gen_op_libs(
+        op_lib_names,
+        sub_directory = "ops/",
+        deps = None,
+        is_external = True,
+        compatible_with = None):
     # Make library out of each op so it can also be used to generate wrappers
     # for various languages.
     if not deps:
@@ -408,7 +413,7 @@ def tf_gen_op_libs(op_lib_names, deps = None, is_external = True, compatible_wit
         cc_library(
             name = n + "_op_lib",
             copts = tf_copts(is_external = is_external),
-            srcs = ["ops/" + n + ".cc"],
+            srcs = [sub_directory + n + ".cc"],
             deps = deps + [clean_dep("//tensorflow/core:framework")],
             compatible_with = compatible_with,
             visibility = ["//visibility:public"],