[llvm] [OFFLOAD] Stricter enforcement of user offload disable (PR #133470)

[via llvm-commits]

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@@ -31,6 +32,12 @@ void initRuntime() {
   if (PM == nullptr)
     PM = new PluginManager();
 
+  if (OffloadPolicy::isOffloadDisabled()) {
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adurang wrote:

The Plugin Manager needs to exist as too many entry points assume that is allocated without ever checking... But it will not go through the normal initialization so the impact is minimal.

https://github.com/llvm/llvm-project/pull/133470