Document two System.Runtime APIs (#2874)

* Document two System.Runtime APIs

* Update RuntimeFeature.xml

* Update RuntimeFeature.xml

* Update AssemblyLoadContext.xml

Author: carlossanlop

xml/System.Runtime.CompilerServices/RuntimeFeature.xml

@@ -76,10 +76,9 @@
         <ReturnType>System.Boolean</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary></summary>
-        <value>Gets a value that determines whether the runtime compiles dynamic code.</value>
-        <remarks>
-          <see langword="true" /> if the runtime compiles dynamic code; <see langword="false" /> if it does not compile dynamic code or doesn't know about this property.</remarks>
+        <summary>Gets a value that indicates whether the runtime compiles dynamic code.</summary>
+        <value><see langword="true" /> if the runtime compiles dynamic code; <see langword="false" /> if it doesn't compile dynamic code or doesn't know about this property.</value>
+        <remarks>To be added.</remarks>
       </Docs>
     </Member>
     <Member MemberName="IsDynamicCodeSupported">
@@ -175,4 +174,4 @@
       </Docs>
     </Member>
   </Members>
-</Type>
+</Type>

xml/System.Runtime.Loader/AssemblyLoadContext.xml

@@ -336,7 +336,7 @@ For more information, see [AssemblyLoadContext.CurrentContextualReflectionContex
       </ReturnValue>
       <Parameters />
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Allows the object to try to free resources and perform other cleanup operations before it's reclaimed by garbage collection.</summary>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>