More analyzer fixes

Author: marek-safar

src/ILLink.Shared/DataFlow/DefaultValueDictionary.cs

@@ -108,5 +108,8 @@ public DefaultValueDictionary<TKey, TValue> Clone ()
 		// Prevent warning CS0659 https://docs.microsoft.com/en-us/dotnet/csharp/misc/cs0659.
 		// This type should never be used as a dictionary key.
 		public override int GetHashCode () => throw new NotImplementedException ();
+
+		public static bool operator ==(DefaultValueDictionary<TKey, TValue> left, DefaultValueDictionary<TKey, TValue> right) => left.Equals(right);
+		public static bool operator !=(DefaultValueDictionary<TKey, TValue> left, DefaultValueDictionary<TKey, TValue> right) => !(left == right);
 	}
 }

src/ILLink.Shared/DataFlow/MaybeLattice.cs

@@ -26,6 +26,9 @@ public Maybe<T> Clone ()
 				return new (copyValue.DeepCopy ());
 			return new (value);
 		}
+
+		public static bool operator ==(Maybe<T> left, Maybe<T> right) => left.Equals(right);
+		public static bool operator !=(Maybe<T> left, Maybe<T> right) => !(left == right);
 	}
 
 	public struct MaybeLattice<T, TValueLattice> : ILattice<Maybe<T>>

src/ILLink.Shared/TypeSystemProxy/WellKnownType.cs

@@ -38,6 +38,7 @@ public static (string Namespace, string Name) GetNamespaceAndName (this WellKnow
 				WellKnownType.System_NotSupportedException => ("System", "NotSupportedException"),
 				WellKnownType.System_Runtime_CompilerServices_DisablePrivateReflectionAttribute => ("System.Runtime.CompilerServices", "DisablePrivateReflectionAttribute"),
 				WellKnownType.System_Void => ("System", "Void"),
+				_ => throw new System.ArgumentException (type)
 			};
 		}
 		public static string GetNamespace (this WellKnownType type) => GetNamespaceAndName (type).Namespace;

src/linker/Linker.Dataflow/ValueNode.cs

@@ -64,5 +64,8 @@ public ValueBasicBlockPair (MultiValue value, int basicBlockIndex)
 		public override bool Equals (object? obj) => obj is ValueBasicBlockPair other && Equals (other);
 
 		public override int GetHashCode () => HashUtils.Combine (Value.GetHashCode (), BasicBlockIndex);
+
+		public static bool operator ==(ValueBasicBlockPair left, ValueBasicBlockPair right) => left.Equals(right);
+		public static bool operator !=(ValueBasicBlockPair left, ValueBasicBlockPair right) => !(left == right);
 	}
 }