Add documentation to all GetDeclaringType APIs.

Author: teo-tsirpanis

src/libraries/System.Reflection.Metadata/src/System/Reflection/Metadata/TypeSystem/EventDefinition.cs

@@ -57,6 +57,9 @@ public CustomAttributeHandleCollection GetCustomAttributes()
             return new CustomAttributeHandleCollection(_reader, Handle);
         }
 
+        /// <summary>
+        /// Returns a handle to the type that declares this event.
+        /// </summary>
         public TypeDefinitionHandle GetDeclaringType()
         {
             return _reader.GetDeclaringType(Handle);

src/libraries/System.Reflection.Metadata/src/System/Reflection/Metadata/TypeSystem/FieldDefinition.cs

@@ -83,6 +83,9 @@ public TType DecodeSignature<TType, TGenericContext>(ISignatureTypeProvider<TTyp
             return decoder.DecodeFieldSignature(ref blob);
         }
 
+        /// <summary>
+        /// Returns a handle to the type that declares this field.
+        /// </summary>
         public TypeDefinitionHandle GetDeclaringType()
         {
             return _reader.GetDeclaringType(Handle);

src/libraries/System.Reflection.Metadata/src/System/Reflection/Metadata/TypeSystem/MethodDefinition.cs

@@ -109,6 +109,9 @@ public MethodImplAttributes ImplAttributes
             }
         }
 
+        /// <summary>
+        /// Returns a handle to the type that declares this method.
+        /// </summary>
         public TypeDefinitionHandle GetDeclaringType()
         {
             return _reader.GetDeclaringType(Handle);

src/libraries/System.Reflection.Metadata/src/System/Reflection/Metadata/TypeSystem/PropertyDefinition.cs

@@ -69,6 +69,9 @@ public CustomAttributeHandleCollection GetCustomAttributes()
             return new CustomAttributeHandleCollection(_reader, Handle);
         }
 
+        /// <summary>
+        /// Returns a handle to the type that declares this property.
+        /// </summary>
         public TypeDefinitionHandle GetDeclaringType()
         {
             return _reader.GetDeclaringType(Handle);