libgomp: Clarify that omp_display_env is fully implemented

libgomp: Clarify that omp_display_env is fully implemented

OpenMP 5.2 added
"When called from within a target region the effect is unspecified."
restriction to omp_display_env, so it is ok not to support it in
target regions (worst case we could add an empty implementation
or one with __builtin_trap in there).

2022-05-17  Jakub Jelinek  <jakub@redhat.com>

	* libgomp.texi (OpenMP 5.1): Remove "Not inside target regions"
	comment for omp_display_env feature.

(cherry picked from commit 741478ed3ed51658af476bccbc198da931e41d44)