Pass blob pointers safely to ETW

internal/etw/ptr64_64.go

@@ -0,0 +1,15 @@
+// +build amd64 arm64
+
+package etw
+
+import (
+	"unsafe"
+)
+
+// byteptr64 defines a struct containing a pointer. The struct is guaranteed to
+// be 64 bits, regardless of the actual size of a pointer on the platform. This
+// is intended for use with certain Windows APIs that expect a pointer as a
+// ULONGLONG.
+type ptr64 struct {
+	ptr unsafe.Pointer
+}