message: Make map_xla_to_scalar_op as a library.
diff: @@ -130,13 +130,25 @@ cc_library(
  alwayslink = 1,
  )
  +cc_library(
  + name = "map_xla_to_scalar_op",
  + srcs = [],
  + hdrs = ["transforms/map_xla_to_scalar_op.h"],
  + deps = [
  + ":hlo",
  + ":lhlo",
  + "@llvm-project//llvm:support",
  + "@llvm-project//mlir:StandardOps",
  + ],
  +)
  +
  cc_library(
  name = "lhlo_legalize_to_affine",
  srcs = ["transforms/lhlo_legalize_to_affine.cc"],
  - hdrs = ["transforms/map_xla_to_scalar_op.h"],
  deps = [
  ":hlo",
  ":lhlo",
  + ":map_xla_to_scalar_op",
  "//tensorflow/compiler/xla:status",
  "@com_google_absl//absl/memory",
  "@llvm-project//llvm:support",
  @@ -151,10 +163,10 @@ cc_library(
  cc_library(
  name = "xla_legalize_to_linalg",
  srcs = ["transforms/xla_legalize_to_linalg.cc"],
  - hdrs = ["transforms/map_xla_to_scalar_op.h"],
  deps = [
  ":hlo",
  ":lhlo",
  + ":map_xla_to_scalar_op",
  "@com_google_absl//absl/memory",
  "@llvm-project//llvm:support",
  "@llvm-project//mlir:IR",
  @@ -169,10 +181,10 @@ cc_library(
  cc_library(
  name = "lhlo_legalize_to_gpu",
  srcs = ["transforms/lhlo_legalize_to_gpu.cc"],
  - hdrs = ["transforms/map_xla_to_scalar_op.h"],
  deps = [
  ":hlo",
  ":lhlo",
  + ":map_xla_to_scalar_op",
  "@com_google_absl//absl/memory",
  "@llvm-project//llvm:support",
  "@llvm-project//mlir:GPUDialect",
  