[llvm] [Offload] Implement `olShutDown` (PR #144055)

[Ross Brunton via llvm-commits]

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@@ -94,15 +94,16 @@ struct AllocInfo {
 };
 
 using AllocInfoMapT = DenseMap<void *, AllocInfo>;
-AllocInfoMapT &allocInfoMap() {
-  static AllocInfoMapT AllocInfoMap{};
-  return AllocInfoMap;
-}
+static AllocInfoMapT *AllocInfoMap;
+AllocInfoMapT &allocInfoMap() { return *AllocInfoMap; }
 
 using PlatformVecT = SmallVector<ol_platform_impl_t, 4>;
-PlatformVecT &Platforms() {
-  static PlatformVecT Platforms;
-  return Platforms;
+static PlatformVecT *PlatformList;
+PlatformVecT &Platforms() { return *PlatformList; }
+
+static std::atomic_int &GlobalRefCount() {
+  static std::atomic_int Ref{0};
+  return Ref;
 }
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RossBrunton wrote:

Mainly for consistency with the (old version) of `Platforms()` and `allocInfoMap()`. In theory it means that Ref isn't initialised until its first use, but in practice initialising an atomic_int probably isn't that expensive.

Does LLVM have a policy for how to handle global state like this?

https://github.com/llvm/llvm-project/pull/144055