Updates for mono/2019-06

3 extension methods extracted from
`System.Threading.Tasks.TaskExtensions` to a new
`System.Threading.Tasks.TaskAsyncEnumerableExtensions` class.

They stay in the same namespace and being extension methods, they
should not break anything.

	public static System.Runtime.CompilerServices.ConfiguredCancelableAsyncEnumerable<T> ConfigureAwait<T> (this System.Collections.Generic.IAsyncEnumerable<T>, bool);
	public static System.Runtime.CompilerServices.ConfiguredAsyncDisposable ConfigureAwait (this System.IAsyncDisposable, bool);
	public static System.Runtime.CompilerServices.ConfiguredCancelableAsyncEnumerable<T> WithCancellation<T> (this System.Collections.Generic.IAsyncEnumerable<T>, System.Threading.CancellationToken);

Context:
dotnet/standard@ebeec50#diff-93ef3714cd10edf17d6d8045cf3406b8,
dotnet/android#3155 (comment)

Author: radekdoulik

reference/System.Core.xml

@@ -18790,27 +18790,6 @@
               <attribute name="System.Runtime.CompilerServices.ExtensionAttribute" />
             </attributes>
             <methods>
-              <method name="ConfigureAwait(System.Collections.Generic.IAsyncEnumerable`1[T], System.Boolean)" attrib="150" static="true" returntype="System.Runtime.CompilerServices.ConfiguredCancelableAsyncEnumerable`1[T]">
-                <attributes>
-                  <attribute name="System.Runtime.CompilerServices.ExtensionAttribute" />
-                </attributes>
-                <parameters>
-                  <parameter name="source" position="0" attrib="0" type="System.Collections.Generic.IAsyncEnumerable`1[T]" direction="this" />
-                  <parameter name="continueOnCapturedContext" position="1" attrib="0" type="System.Boolean" />
-                </parameters>
-                <generic-parameters>
-                  <generic-parameter name="T" attributes="0" />
-                </generic-parameters>
-              </method>
-              <method name="ConfigureAwait(System.IAsyncDisposable, System.Boolean)" attrib="150" static="true" returntype="System.Runtime.CompilerServices.ConfiguredAsyncDisposable">
-                <attributes>
-                  <attribute name="System.Runtime.CompilerServices.ExtensionAttribute" />
-                </attributes>
-                <parameters>
-                  <parameter name="source" position="0" attrib="0" type="System.IAsyncDisposable" direction="this" />
-                  <parameter name="continueOnCapturedContext" position="1" attrib="0" type="System.Boolean" />
-                </parameters>
-              </method>
               <method name="Unwrap(System.Threading.Tasks.Task`1[System.Threading.Tasks.Task])" attrib="150" static="true" returntype="System.Threading.Tasks.Task">
                 <attributes>
                   <attribute name="System.Runtime.CompilerServices.ExtensionAttribute" />
@@ -18830,18 +18809,6 @@
                   <generic-parameter name="TResult" attributes="0" />
                 </generic-parameters>
               </method>
-              <method name="WithCancellation(System.Collections.Generic.IAsyncEnumerable`1[T], System.Threading.CancellationToken)" attrib="150" static="true" returntype="System.Runtime.CompilerServices.ConfiguredCancelableAsyncEnumerable`1[T]">
-                <attributes>
-                  <attribute name="System.Runtime.CompilerServices.ExtensionAttribute" />
-                </attributes>
-                <parameters>
-                  <parameter name="source" position="0" attrib="0" type="System.Collections.Generic.IAsyncEnumerable`1[T]" direction="this" />
-                  <parameter name="cancellationToken" position="1" attrib="0" type="System.Threading.CancellationToken" />
-                </parameters>
-                <generic-parameters>
-                  <generic-parameter name="T" attributes="0" />
-                </generic-parameters>
-              </method>
             </methods>
           </class>
         </classes>

reference/mscorlib.xml

@@ -117337,6 +117337,46 @@
               </method>
             </methods>
           </class>
+          <class name="TaskAsyncEnumerableExtensions" type="class" base="System.Object" sealed="true" abstract="true" charset="Ansi" layout="Auto">
+            <attributes>
+              <attribute name="System.Runtime.CompilerServices.ExtensionAttribute" />
+            </attributes>
+            <methods>
+              <method name="ConfigureAwait(System.Collections.Generic.IAsyncEnumerable`1[T], System.Boolean)" attrib="150" static="true" returntype="System.Runtime.CompilerServices.ConfiguredCancelableAsyncEnumerable`1[T]">
+                <attributes>
+                  <attribute name="System.Runtime.CompilerServices.ExtensionAttribute" />
+                </attributes>
+                <parameters>
+                  <parameter name="source" position="0" attrib="0" type="System.Collections.Generic.IAsyncEnumerable`1[T]" direction="this" />
+                  <parameter name="continueOnCapturedContext" position="1" attrib="0" type="System.Boolean" />
+                </parameters>
+                <generic-parameters>
+                  <generic-parameter name="T" attributes="0" />
+                </generic-parameters>
+              </method>
+              <method name="ConfigureAwait(System.IAsyncDisposable, System.Boolean)" attrib="150" static="true" returntype="System.Runtime.CompilerServices.ConfiguredAsyncDisposable">
+                <attributes>
+                  <attribute name="System.Runtime.CompilerServices.ExtensionAttribute" />
+                </attributes>
+                <parameters>
+                  <parameter name="source" position="0" attrib="0" type="System.IAsyncDisposable" direction="this" />
+                  <parameter name="continueOnCapturedContext" position="1" attrib="0" type="System.Boolean" />
+                </parameters>
+              </method>
+              <method name="WithCancellation(System.Collections.Generic.IAsyncEnumerable`1[T], System.Threading.CancellationToken)" attrib="150" static="true" returntype="System.Runtime.CompilerServices.ConfiguredCancelableAsyncEnumerable`1[T]">
+                <attributes>
+                  <attribute name="System.Runtime.CompilerServices.ExtensionAttribute" />
+                </attributes>
+                <parameters>
+                  <parameter name="source" position="0" attrib="0" type="System.Collections.Generic.IAsyncEnumerable`1[T]" direction="this" />
+                  <parameter name="cancellationToken" position="1" attrib="0" type="System.Threading.CancellationToken" />
+                </parameters>
+                <generic-parameters>
+                  <generic-parameter name="T" attributes="0" />
+                </generic-parameters>
+              </method>
+            </methods>
+          </class>
           <class name="TaskCanceledException" type="class" base="System.OperationCanceledException" serializable="true" charset="Ansi" layout="Auto">
             <interfaces>
               <interface name="System.Runtime.Serialization.ISerializable" />