[libunwind] [libunwind][WebAssembly] Omit unused parts of libunwind.cpp for Wasm (PR #73196)

[Kazushi Marukawa via cfe-commits]

================
@@ -26,7 +26,7 @@
 #include <sanitizer/asan_interface.h>
 #endif
 
-#if !defined(__USING_SJLJ_EXCEPTIONS__)
+#if !defined(__USING_SJLJ_EXCEPTIONS__) || !defined(__USING_WASM_EXCEPTIONS__)
----------------
kaz7 wrote:

This must be `#if !defined(__USING_SJLJ_EXCEPTIONS__) && !defined(__USING_WASM_EXCEPTIONS__)` since we don't want to compile this code for either sjlj or wasm users.  `not (sjlj || wasm)` is equal to `not(sjlj) && not(wasm)` as you know...

VE use only SjLj, so it should be warnned by the buildbot for VE, but our buildbot has been stopped last 2 months.  I've noticed this problem when I've been trying to recover our buildbot.  ;-)

https://github.com/llvm/llvm-project/pull/73196