[libcxxabi] [libunwind] [libcxx] [libunwind][libcxx][libcxxabi] Fix Exception Handling build for wasm (PR #79667)

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@@ -35,7 +32,12 @@ struct _Unwind_LandingPadContext {
 
 // Communication channel between compiler-generated user code and personality
 // function
-thread_local struct _Unwind_LandingPadContext __wasm_lpad_context;
+#if __STDC_VERSION__ >= 202311L
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trcrsired wrote:

thread.h does not exist.

https://github.com/llvm/llvm-project/pull/79667