algorithm_test: suppress bogus -Wnonnull warning in GCC 12

Upstream bug report: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105705

PiperOrigin-RevId: 454937873
Change-Id: I44f940caf36d83714af765f01cc43c5143fe21c3
diff --git a/absl/algorithm/algorithm_test.cc b/absl/algorithm/algorithm_test.cc
index 81fccb6..d18df02 100644
--- a/absl/algorithm/algorithm_test.cc
+++ b/absl/algorithm/algorithm_test.cc
@@ -20,6 +20,7 @@
 
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
+#include "absl/base/config.h"
 
 namespace {
 
@@ -50,7 +51,15 @@
   std::vector<int> empty1;
   std::vector<int> empty2;
 
+  // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105705
+#if ABSL_INTERNAL_HAVE_MIN_GNUC_VERSION(12, 0)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wnonnull"
+#endif
   EXPECT_FALSE(absl::equal(v1.begin(), v1.end(), empty1.begin(), empty1.end()));
+#if ABSL_INTERNAL_HAVE_MIN_GNUC_VERSION(12, 0)
+#pragma GCC diagnostic pop
+#endif
   EXPECT_FALSE(absl::equal(empty1.begin(), empty1.end(), v1.begin(), v1.end()));
   EXPECT_TRUE(
       absl::equal(empty1.begin(), empty1.end(), empty2.begin(), empty2.end()));