Add missing #includes

PiperOrigin-RevId: 969935575
Change-Id: I1159f88d02479495df8d90b230f679aff8a5da91

absl/synchronization/internal/create_thread_identity.h

diff --git a/absl/synchronization/internal/create_thread_identity.h b/absl/synchronization/internal/create_thread_identity.h
index 4cfde09..f8bfbe9 100644
--- a/absl/synchronization/internal/create_thread_identity.h
+++ b/absl/synchronization/internal/create_thread_identity.h
@@ -26,6 +26,7 @@
 #define ABSL_SYNCHRONIZATION_INTERNAL_CREATE_THREAD_IDENTITY_H_
 
 #include "absl/base/internal/thread_identity.h"
+#include "absl/base/optimization.h"
 #include "absl/base/port.h"
 
 namespace absl {

absl/synchronization/internal/graphcycles_test.cc

diff --git a/absl/synchronization/internal/graphcycles_test.cc b/absl/synchronization/internal/graphcycles_test.cc
index 9e44a58..d4ba0f6 100644
--- a/absl/synchronization/internal/graphcycles_test.cc
+++ b/absl/synchronization/internal/graphcycles_test.cc
@@ -20,6 +20,7 @@
 #include <iterator>
 #include <map>
 #include <random>
+#include <string>
 #include <unordered_set>
 #include <utility>
 #include <vector>