Merge branch 'cmstd-IBM-i' into release-3.16

Merge-request: !4430

CMakeLists.txt

@@ -368,7 +368,7 @@ macro (CMAKE_BUILD_UTILITIES)
   # Setup third-party libraries.
   # Everything in the tree should be able to include files from the
   # Utilities directory.
-  if (CMAKE_SYSTEM_NAME STREQUAL "AIX" AND CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+  if ((CMAKE_SYSTEM_NAME STREQUAL "AIX" OR CMAKE_SYSTEM_NAME STREQUAL "OS400") AND CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
     # using -isystem option generate error "template with C linkage"
     include_directories("${CMake_SOURCE_DIR}/Utilities/std")
   else()