Add an IWYU pragma to vlog_is_on.h

PiperOrigin-RevId: 595114487
Change-Id: Ia8fc94e4feaf8da1185e7e93ba4250e61e690cfd

absl/log/vlog_is_on.h

@@ -58,6 +58,8 @@
 
 
 #include "absl/log/absl_vlog_is_on.h"  // IWYU pragma: export
 #include "absl/log/absl_vlog_is_on.h"  // IWYU pragma: export
 
 
+// IWYU pragma: private, include "absl/log/log.h"
+
 // Each VLOG_IS_ON call site gets its own VLogSite that registers with the
 // Each VLOG_IS_ON call site gets its own VLogSite that registers with the
 // global linked list of sites to asynchronously update its verbosity level on
 // global linked list of sites to asynchronously update its verbosity level on
 // changes to --v or --vmodule. The verbosity can also be set by manually
 // changes to --v or --vmodule. The verbosity can also be set by manually