[clang-tools-extra] [clangd] Re-land "support outgoing calls in call hierarchy" (PR #117673)

[kadir çetinkaya via cfe-commits]

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@@ -69,7 +69,7 @@ enum class DuplicateHandling {
 /// locking when we swap or obtain references to snapshots.
 class FileSymbols {
 public:
-  FileSymbols(IndexContents IdxContents);
+  FileSymbols(IndexContents IdxContents, bool SupportContainedRefs = true);
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kadircet wrote:

can we avoid the default param here?

https://github.com/llvm/llvm-project/pull/117673