[llvm] [Bazel] Support opt-driver library, like clang-driver (PR #79205)

[William Moses via llvm-commits]

https://github.com/wsmoses updated https://github.com/llvm/llvm-project/pull/79205

>From 8d72175a4a067ead32c30c8e8bdc618a447045b4 Mon Sep 17 00:00:00 2001
From: "William S. Moses" <gh at wsmoses.com>
Date: Tue, 23 Jan 2024 15:17:10 -0500
Subject: [PATCH] [CMake/Bazel] Support usage of opt driver as a library

---
 llvm/tools/opt/CMakeLists.txt                     | 12 +++++++++---
 utils/bazel/llvm-project-overlay/llvm/BUILD.bazel | 11 ++++++++---
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/llvm/tools/opt/CMakeLists.txt b/llvm/tools/opt/CMakeLists.txt
index 2cdb99e936287ca..fbf7753e5c61029 100644
--- a/llvm/tools/opt/CMakeLists.txt
+++ b/llvm/tools/opt/CMakeLists.txt
@@ -1,4 +1,12 @@
+add_llvm_component_library(LLVMOptDriver
+  NewPMDriver.cpp
+  opt.cpp
+  DEPENDS
+  intrinsics_gen
+)
+
 set(LLVM_LINK_COMPONENTS
+  OptDriver
   AllTargetsAsmParsers
   AllTargetsCodeGens
   AllTargetsDescs
@@ -30,11 +38,9 @@ set(LLVM_LINK_COMPONENTS
   )
 
 add_llvm_tool(opt
-  NewPMDriver.cpp
-  opt.cpp
-
   DEPENDS
   intrinsics_gen
   SUPPORT_PLUGINS
   )
+set_target_properties(opt PROPERTIES LINKER_LANGUAGE CXX)
 export_executable_symbols_for_plugins(opt)
diff --git a/utils/bazel/llvm-project-overlay/llvm/BUILD.bazel b/utils/bazel/llvm-project-overlay/llvm/BUILD.bazel
index b22ec01376be6d4..21466a79af61b53 100644
--- a/utils/bazel/llvm-project-overlay/llvm/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/llvm/BUILD.bazel
@@ -4808,8 +4808,8 @@ cc_binary(
     ],
 )
 
-cc_binary(
-    name = "opt",
+cc_library(
+    name = "opt-driver",
     srcs = glob([
         "tools/opt/*.cpp",
         "tools/opt/*.h",
@@ -4820,7 +4820,6 @@ cc_binary(
         "@platforms//os:macos": [],
         "//conditions:default": ["-Wl,--export-dynamic"],
     }),
-    stamp = 0,
     deps = [
         ":AllTargetsAsmParsers",
         ":AllTargetsCodeGens",
@@ -4847,6 +4846,12 @@ cc_binary(
     ],
 )
 
+cc_binary(
+    name = "opt",
+    stamp = 0,
+    deps = [":opt-driver"]
+)
+
 gentbl(
     name = "SancovOptsTableGen",
     strip_include_prefix = "tools/sancov",