[SYCL] Move sycl_ext_oneapi_group_load_store to experimental (#15419)

Author: aelovikov-intel

sycl/doc/extensions/deprecated/sycl_ext_oneapi_group_load_store.asciidoc

@@ -23,8 +23,9 @@ NOTE: Khronos(R) is a registered trademark and SYCL(TM) and SPIR(TM) are
 trademarks of The Khronos Group Inc.  OpenCL(TM) is a trademark of Apple Inc.
 used by permission by Khronos.
 
-NOTE: This extension has been replaced with a new version under the same name
-that completely changed the interfaces.
+NOTE: This extension has been replaced with a
+link:../experimental/sycl_ext_oneapi_group_load_store.asciidoc[`new version`]
+under the same name that completely changed the interfaces.
 
 == Notice
 

sycl/doc/extensions/proposed/sycl_ext_oneapi_group_load_store.asciidoc renamed to sycl/doc/extensions/experimental/sycl_ext_oneapi_group_load_store.asciidoc

@@ -40,11 +40,12 @@ This extension also depends on the following other SYCL extensions:
 
 == Status
 
-This is a proposed extension specification, intended to gather community
-feedback.  Interfaces defined in this specification may not be implemented yet
-or may be in a preliminary state.  The specification itself may also change in
-incompatible ways before it is finalized.  *Shipping software products should
-not rely on APIs defined in this specification.*
+This is an experimental extension specification, intended to provide early
+access to features and gather community feedback.  Interfaces defined in this
+specification are implemented in {dpcpp}, but they are not finalized and may
+change incompatibly in future versions of {dpcpp} without prior notice.
+*Shipping software products should not rely on APIs defined in this
+specification.*
 
 == Overview