Improve sanitizer detection

__has_feature(leak_sanitizer) cannot be used to detect the existence of LSan.

Author: kleisauke

system/include/emscripten/bind.h

@@ -22,7 +22,7 @@
 #include <emscripten/val.h>
 #include <emscripten/wire.h>
 
-#if __has_feature(leak_sanitizer) || __has_feature(address_sanitizer)
+#if defined(HAS_LSAN) || __has_feature(address_sanitizer)
 #include <sanitizer/lsan_interface.h>
 #endif
 
@@ -605,7 +605,7 @@ template<typename T>
 inline T* getContext(const T& t) {
     // not a leak because this is called once per binding
     auto* ret = new T(t);
-#if __has_feature(leak_sanitizer) || __has_feature(address_sanitizer)
+#if defined(HAS_LSAN) || __has_feature(address_sanitizer)
     __lsan_ignore_object(ret);
 #endif
     return ret;