std tests: use __OsLocalKeyInner from realstd
This is basically the same as https://github.com/rust-lang/rust/pull/100201, but for __OsLocalKeyInner:
Some std tests are failing in Miri on Windows because [this static](a377893da2/library/std/src/sys/windows/thread_local_key.rs (L234-L239)) is getting duplicated, and Miri does not handle that properly -- Miri does not support this magic `.CRT$XLB` linker section, but instead just looks up this particular hard-coded static in the standard library. This PR lets the test suite use the std static instead of having its own copy.
Fixes https://github.com/rust-lang/miri/issues/2754
r? `@thomcc`
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