Consolidate RM service into PD session

This patch integrates three region maps into each PD session to
reduce the session overhead and to simplify the PD creation procedure.
Please refer to the issue cited below for an elaborative discussion.

Note the API change:

With this patch, the semantics of core's RM service have changed. Now,
the service is merely a tool for creating and destroying managed
dataspaces, which are rarely needed. Regular components no longer need a
RM session. For this reason, the corresponding argument for the
'Process' and 'Child' constructors has been removed.

The former interface of the 'Rm_session' is not named 'Region_map'. As a
minor refinement, the 'Fault_type' enum values are now part of the
'Region_map::State' struct.

Issue #1938

repos/base-linux/run/region_map_mmap.run

@@ -1,4 +1,4 @@
-build "core init test/rm_session_mmap drivers/timer test/signal"
+build "core init test/region_map_mmap drivers/timer test/signal"
 
 create_boot_directory
 
@@ -20,7 +20,7 @@ install_config {
 		<default-route>
 			<any-service> <parent/> <any-child/> </any-service>
 		</default-route>
-		<start name="test-rm_session_mmap">
+		<start name="test-region_map_mmap">
 			<resource name="RAM" quantum="2M"/>
 		</start>
 
@@ -34,7 +34,7 @@ install_config {
 		</start>
 	</config>}
 
-build_boot_image "core init test-rm_session_mmap timer test-signal"
+build_boot_image "core init test-region_map_mmap timer test-signal"
 
 run_genode_until forever