Help: Add docs for new compilers supporting language standards.

Help/manual/cmake-compile-features.7.rst

@@ -343,9 +343,25 @@ and :prop_gbl:`compile features <CMAKE_C_KNOWN_FEATURES>` available from
 the following :variable:`compiler ids <CMAKE_<LANG>_COMPILER_ID>` as of the
 versions specified for each:
 
-* all compilers and versions listed above for C++
+* all compilers and versions listed above for C++.
 * ``GNU``: GNU compiler versions 3.4 through 5.0.
 
+CMake is currently aware of the :prop_tgt:`C++ standards <CXX_STANDARD>` and
+thier associated meta-features (e.g. ``cxx_std_11``) available from the
+following :variable:`compiler ids <CMAKE_<LANG>_COMPILER_ID>` as of the
+versions specified for each:
+
+* ``Cray``: Cray Compiler Environment version 8.1 through 8.5.8.
+* ``PGI``: PGI version 12.10 through 17.5.
+* ``XL``: IBM XL version 10.1 through 13.1.5.
+
+CMake is currently aware of the :prop_tgt:`C standards <C_STANDARD>` and
+thier associated meta-features (e.g. ``c_std_99``) available from the
+following :variable:`compiler ids <CMAKE_<LANG>_COMPILER_ID>` as of the
+versions specified for each:
+
+* all compilers and versions listed above with only meta-features for C++.
+
 CMake is currently aware of the :prop_tgt:`CUDA standards <CUDA_STANDARD>`
 from the following :variable:`compiler ids <CMAKE_<LANG>_COMPILER_ID>` as of the
 versions specified for each:

Help/release/3.9.rst

@@ -17,6 +17,11 @@ Languages
   for VS 2010 and above.  This complements the existing support by the
   :ref:`Makefile Generators` and the :generator:`Ninja` generator.
 
+* CMake is now aware of the :prop_tgt:`C++ standards <CXX_STANDARD>` and
+  :prop_tgt:`C standards <C_STANDARD>` and thier associated meta-features for
+  the following :variable:`compiler ids <CMAKE_<LANG>_COMPILER_ID>`: ``Cray``,
+  ``PGI``, and ``XL``.
+
 Generators
 ----------