Document Kernel.free-memory and Kernel.total-memory

doc/Type/Kernel.pod6

@@ -53,6 +53,22 @@ Instance / Class method returning the number of CPU cores that are available.
 Instance / Class method returning the amount of CPU uses since the start of
 the program (in microseconds).
 
+=head2 method free-memory
+
+    method free-memory(--> Int)
+
+Instance / Class method returning the available memory on the system. When
+using the JVM, this returns the available memory to the JVM instead. This
+method is only available in release v2019.06 and later.
+
+=head2 method total-memory
+
+    method total-memory(--> Int)
+
+Instance / Class method returning the total memory available to the system.
+When using the JVM, this returns the total memory available to the JVM instead.
+This method is only available in release v2019.06 and later.
+
 =head2 method desc
 
     method desc(--> Str)