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

[Louis Dionne via cfe-commits]

================
@@ -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
----------------
ldionne wrote:

We always compile the built library with C++23, so I don't understand this change.

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