Add a use of C++20 features as a test, to see if it works in all downstream consumers.

PiperOrigin-RevId: 776248536

.bazelrc

diff --git a/.bazelrc b/.bazelrc
index 3b2dcc0..497497d 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -1,7 +1,7 @@
 # Automatically detect host platform to pick config
 common --enable_platform_specific_config
 
-build --cxxopt=-std=c++17
+build --cxxopt=-std=c++20
 build --cxxopt=-fno-rtti
 
 # Enable Abseil/Googletest integration

quiche/quic/core/quic_types.h

diff --git a/quiche/quic/core/quic_types.h b/quiche/quic/core/quic_types.h
index fc42d29..1db5d3f 100644
--- a/quiche/quic/core/quic_types.h
+++ b/quiche/quic/core/quic_types.h
@@ -953,10 +953,7 @@
                            std::to_string(ce));
   }
 
-  bool operator==(const QuicEcnCounts& other) const {
-    return (this->ect0 == other.ect0 && this->ect1 == other.ect1 &&
-            this->ce == other.ce);
-  }
+  bool operator==(const QuicEcnCounts& other) const = default;
 
   QuicPacketCount ect0 = 0;
   QuicPacketCount ect1 = 0;