[llvm] [OFFLOAD] Add plugin with support for Intel oneAPI Level Zero (PR #158900)

[Alex Duran via llvm-commits]

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@@ -16,17 +16,93 @@
 #include <list>
 #include <memory>
 #include <mutex>
+#include <type_traits>
+
+template <typename ObjectType> struct PerThread {
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adurang wrote:

I introduced the PerThread table to manage some static storage related to Interop. In the plugin, this is used more extensively but the current PerThread didn't support exactly what was needed.
So I reworked it to be a bit more generic and cover the plugin usages  (because I realized I was just rewritting 90% of this again for the plugin).

Other plugins don't have static data AFAIK. But this is just an auxilary data structure so it's not like they couldn't use it if needed.

https://github.com/llvm/llvm-project/pull/158900