libgomp.texi: Add more to-be-implemented OpenMP 5.2 features

libgomp/
	* libgomp.texi (Other new OpenMP 5.1 features): Add
	'begin declare target'.
	(Other new OpenMP 5.2 features): New.

libgomp/libgomp.texi

@@ -343,6 +343,7 @@ The OpenMP 4.5 specification is fully supported.
 @item Support of structured block sequences in C/C++ @tab Y @tab
 @item @code{unconstrained} and @code{reproducible} modifiers on @code{order}
       clause @tab Y @tab
+@item Support @code{begin/end declare target} syntax in C/C++ @tab N @tab
 @end multitable
 
 
@@ -387,7 +388,8 @@ The OpenMP 4.5 specification is fully supported.
 @item @code{allocate} and @code{firstprivate} clauses on @code{scope}
       @tab N @tab
 @item @code{ompt_callback_work} @tab N @tab
-@item Extended map-type handling of @code{target enter/exit data} @tab N @tab
+@item Default map-type for @code{map} clause in @code{target enter/exit data}
+      @tab N @tab
 @item New @code{doacross} clause as alias for @code{depend} with
       @code{source}/@code{sink} modifier @tab N @tab
 @item Deprecation of @code{depend} with @code{source}/@code{sink} modifier
@@ -395,6 +397,19 @@ The OpenMP 4.5 specification is fully supported.
 @item @code{omp_cur_iteration} keyword @tab N @tab
 @end multitable
 
+@unnumberedsubsec Other new OpenMP 5.2 features
+
+@multitable @columnfractions .60 .10 .25
+@headitem Description @tab Status @tab Comments
+@item For Fortran, optional comma between directive and clause @tab N @tab
+@item Conforming device numbers and @code{omp_initial_device} and
+      @code{omp_invalid_device} enum/PARAMETER @tab N @tab
+@item Initial value of @emph{default-device-var} ICV with
+      @code{OMP_TARGET_OFFLOAD=mandatory} @tab N @tab
+@item @emph{interop_types} in any position of the modifier list for the @code{init} clause
+      of the @code{interop} construct @tab N @tab
+@end multitable
+
 
 @c ---------------------------------------------------------------------
 @c OpenMP Runtime Library Routines