[compiler-rt][iwyu] explicitly includes `<new>` in xray_utils.cpp

Compiling compiler-rt with Clang modules and libc++ revealed that the
global `operator new` is being called without including `<new>`.

Differential Revision: https://reviews.llvm.org/D105401

compiler-rt/lib/xray/xray_utils.cpp

@@ -20,6 +20,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <iterator>
+#include <new>
 #include <stdlib.h>
 #include <sys/types.h>
 #include <tuple>