change log for v3.1.1 (#1562)

* start the change log for v3.1.1

* update change log

* fix typo

* update change log

* update change log

Author: bashbaug

api/appendix_e.asciidoc

@@ -760,3 +760,7 @@ Other changes in OpenCL 3.1:
       ** {cl_khr_subgroup_shuffle_EXT}
       ** {cl_khr_subgroup_shuffle_relative_EXT}
       ** {cl_khr_suggested_local_work_size_EXT}
+
+Changes from *v3.1.0* to *v3.1.1*:
+
+  * Reverted the change where observing that an event is {CL_COMPLETE} is a synchronization point due to possible performance regressions, see internal issue 386 and {khronos-opencl-pr}/1558[#1558].

c/appendix_a.asciidoc

@@ -92,3 +92,10 @@ Other changes in OpenCL 3.1:
       ** {cl_khr_subgroup_rotate_EXT}
       ** {cl_khr_subgroup_shuffle_EXT}
       ** {cl_khr_subgroup_shuffle_relative_EXT}
+
+Changes from *v3.1.0* to *v3.1.1*:
+
+  * Clarified that the version requirements in this OpenCL C spec are for the OpenCL C language version, not the OpenCL device or platform version, see {khronos-opencl-pr}/1557[#1557].
+  * Clarified the description of the `andy` and `all` functions, see {khronos-opencl-pr}/1561[#1561].
+  * {cl_khr_fp16_EXT}
+      ** Clarified that the `halfn` vector data type is not a reserved data type when the extension is supported, see {khronos-opencl-pr}/1548[#1548].