[CGData][ThinLTO][NFC] Prep for two-codegen rounds (#90934)

This is NFC for https://github.com/llvm/llvm-project/pull/90933.

- Create a lambda function, `RunBackends`, to group the backend
operations into a single function.
- Explicitly pass the `CodeGenOnly` argument to thinBackend, instead of
depending on a configuration value.

Depends on https://github.com/llvm/llvm-project/pull/90304.
This is a patch for
https://discourse.llvm.org/t/rfc-enhanced-machine-outliner-part-2-thinlto-nolto/78753.

1 files changed, 4 insertions, 4 deletions

diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 62c6a57..abc936f 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -1321,10 +1321,10 @@ static void runThinLTOBackend(
     Conf.CGFileType = getCodeGenFileType(Action);
     break;
   }
-  if (Error E =
-          thinBackend(Conf, -1, AddStream, *M, *CombinedIndex, ImportList,
-                      ModuleToDefinedGVSummaries[M->getModuleIdentifier()],
-                      /* ModuleMap */ nullptr, CGOpts.CmdArgs)) {
+  if (Error E = thinBackend(
+          Conf, -1, AddStream, *M, *CombinedIndex, ImportList,
+          ModuleToDefinedGVSummaries[M->getModuleIdentifier()],
+          /* ModuleMap */ nullptr, Conf.CodeGenOnly, CGOpts.CmdArgs)) {
     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
       errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
     });