Help: CMAKE_NO_BUILTIN_CHRPATH applies to XCOFF too

Help/variable/CMAKE_NO_BUILTIN_CHRPATH.rst

@@ -1,10 +1,17 @@
 CMAKE_NO_BUILTIN_CHRPATH
 ------------------------
 
-Do not use the builtin ELF editor to fix RPATHs on installation.
+Do not use the builtin binary editor to fix runtime library search
+paths on installation.
 
-When an ELF binary needs to have a different RPATH after installation
-than it does in the build tree, CMake uses a builtin editor to change
-the RPATH in the installed copy.  If this variable is set to true then
-CMake will relink the binary before installation instead of using its
-builtin editor.
+When an ELF or XCOFF binary needs to have a different runtime library
+search path after installation than it does in the build tree, CMake uses
+a builtin editor to change the runtime search path in the installed copy.
+If this variable is set to true then CMake will relink the binary before
+installation instead of using its builtin editor.
+
+.. versionadded:: 3.20
+
+  This variable also applies to XCOFF binaries' LIBPATH.  Prior to the
+  addition of the XCOFF editor in CMake 3.20, this variable applied only
+  to ELF binaries' RPATH/RUNPATH.