[libcxxabi] [libunwind] [llvm] fix Wasm exceptions + coop threading + shared libraries (PR #222747)

[Heejin Ahn via cfe-commits]

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@@ -1882,6 +1882,9 @@ defset list<RuntimeLibcallImpl> SjLjExceptionHandlingLibcalls = {
   def _Unwind_SjLj_Unregister : RuntimeLibcallImpl<UNWIND_UNREGISTER>;
 }
 
+// Only used on wasm
+def _Unwind_GetWasmLPadContext : RuntimeLibcallImpl<UNWIND_GET_WASM_LPAD_CONTEXT>;
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aheejin wrote:

I guess we should add this to `WasmSystemLibrary` too

https://github.com/llvm/llvm-project/pull/222747