[libunwind][WebAssembly] Omit unused parts of libunwind.cpp for Wasm

Wasm doesn't use most of that file; Wasm does not allow access of system
registers and those functionalities are provided from the VM.

Author: aheejin

libunwind/src/libunwind.cpp

@@ -26,7 +26,7 @@
 #include <sanitizer/asan_interface.h>
 #endif
 
-#if !defined(__USING_SJLJ_EXCEPTIONS__)
+#if !defined(__USING_SJLJ_EXCEPTIONS__) || !defined(__USING_WASM_EXCEPTIONS__)
 #include "AddressSpace.hpp"
 #include "UnwindCursor.hpp"
 
@@ -347,7 +347,8 @@ void __unw_remove_dynamic_eh_frame_section(unw_word_t eh_frame_start) {
 }
 
 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
-#endif // !defined(__USING_SJLJ_EXCEPTIONS__)
+#endif // !defined(__USING_SJLJ_EXCEPTIONS__) ||
+       // !defined(__USING_WASM_EXCEPTIONS__)
 
 #ifdef __APPLE__