[llvm] [DenseMap] Share rehash and grow for relocatable bucket types. NFC (PR #225018)

[Alexis Engelke via llvm-commits]

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@@ -56,6 +56,9 @@ template <typename T, typename Enable = void> struct DenseMapInfo {
 // Provide DenseMapInfo for all pointers. Avoid requiring T to be complete so
 // clients can instantiate DenseMap<T*, ...> with forward declared key types.
 template <typename T> struct DenseMapInfo<T *> {
+  // Select InlinePtrHash in DenseMap.cpp.
+  using PointerValueHash = DenseMapInfo;
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aengelke wrote:

Just use a static constexpr bool?

https://github.com/llvm/llvm-project/pull/225018