[compiler-rt] [XRay] Always register constructor(0) alongside .preinit_array (PR #188788)

[Sebastian Kreutzer via llvm-commits]

================
@@ -21,6 +21,12 @@
 #include <utility>
 
 extern "C" {
+
+// Ensure XRay is initialized. Safe to call multiple times; the first call
+// performs flag parsing, sled registration, and (if requested) pre-main
+// patching.  Subsequent calls return immediately.
+extern void __xray_init();
----------------
sebastiankreutzer wrote:

This is already declared in the public interface (which is included here), so unless I'm missing something, this shouldn't be needed. 

https://github.com/llvm/llvm-project/pull/188788