[clang-tools-extra] [clangd] Support .clangd command line modifications for C++ modules (PR #122606)

[Petr Polezhaev via cfe-commits]

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@@ -833,8 +833,8 @@ bool OverlayCDB::setCompileCommand(PathRef File,
 std::unique_ptr<ProjectModules>
 OverlayCDB::getProjectModules(PathRef File) const {
   auto MDB = DelegatingCDB::getProjectModules(File);
-  MDB->setCommandProvider([&Mangler = Mangler](tooling::CompileCommand &Command,
-                                               PathRef CommandPath) {
+  MDB->setCommandMangler([&Mangler = Mangler](tooling::CompileCommand &Command,
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petr-polezhaev wrote:

@kadircet this is what I was talking about with unsafe reference capturing. The solution (while keeping lambda compatibility for unit-tests) would be to make the function copyable but pass the Mangler by the `shared_ptr` into the very first instance.

https://github.com/llvm/llvm-project/pull/122606