OpenMP: Require target and/or targetsync init modifier [PR118965]

OpenMP: Require target and/or targetsync init modifier [PR118965]

As noted in PR 118965, the initial interop implementation overlooked
the requirement in the OpenMP spec that at least one of the "target"
and "targetsync" modifiers is required in both the interop construct
init clause and the declare variant append_args clause.

Adding the check was fairly straightforward, but it broke about a
gazillion existing test cases.  In particular, things like "init (x, y)"
which were previously accepted (and tested for being accepted) aren't
supposed to be allowed by the spec, much less things like "init (target)"
where target was previously interpreted as a variable name instead of a
modifier.  Since one of the effects of the change is that at least one
modifier is always required, I found that deleting all the code that was
trying to detect and handle the no-modifier case allowed for better
diagnostics.

gcc/c/ChangeLog
	PR middle-end/118965
	* c-parser.cc (c_parser_omp_clause_init_modifiers): Adjust
	error message.
	(c_parser_omp_clause_init): Remove code for recognizing clauses
	without modifiers.  Diagnose missing target/targetsync modifier.
	(c_finish_omp_declare_variant): Diagnose missing target/targetsync
	modifier.

gcc/cp/ChangeLog
	PR middle-end/118965
	* parser.cc (c_parser_omp_clause_init_modifiers): Adjust
	error message.
	(cp_parser_omp_clause_init): Remove code for recognizing clauses
	without modifiers.  Diagnose missing target/targetsync modifier.
	(cp_finish_omp_declare_variant): Diagnose missing target/targetsync
	modifier.

gcc/fortran/ChangeLog
	PR middle-end/118965
	* openmp.cc (gfc_parser_omp_clause_init_modifiers): Fix some
	inconsistent code indentation.  Remove code for recognizing
	clauses	without modifiers.  Diagnose prefer_type without a
	following paren.  Adjust error message for an unrecognized modifier.
	Diagnose missing target/targetsync modifier.
	(gfc_match_omp_init): Fix more inconsistent code indentation.

gcc/testsuite/ChangeLog
	PR middle-end/118965
	* c-c++-common/gomp/append-args-1.c: Add target/targetsync
	modifiers so tests do what they were previously supposed to do.
	Adjust expected output.
	* c-c++-common/gomp/append-args-7.c: Likewise.
	* c-c++-common/gomp/append-args-8.c: Likewise.
	* c-c++-common/gomp/append-args-9.c: Likewise.
	* c-c++-common/gomp/interop-1.c: Likewise.
	* c-c++-common/gomp/interop-2.c: Likewise.
	* c-c++-common/gomp/interop-3.c: Likewise.
	* c-c++-common/gomp/interop-4.c: Likewise.
	* c-c++-common/gomp/pr118965-1.c: New.
	* c-c++-common/gomp/pr118965-2.c: New.
	* g++.dg/gomp/append-args-1.C: Add target/targetsync modifiers
	and adjust expected output.
	* g++.dg/gomp/append-args-2.C: Likewise.
	* g++.dg/gomp/append-args-6.C: Likewise.
	* g++.dg/gomp/append-args-7.C: Likewise.
	* g++.dg/gomp/append-args-8.C: Likewise.
	* g++.dg/gomp/interop-5.C: Likewise.
	* gfortran.dg/gomp/append_args-1.f90: Add target/targetsync
	modifiers and adjust expected output.
	* gfortran.dg/gomp/append_args-2.f90: Likewise.
	* gfortran.dg/gomp/append_args-3.f90: Likewise.
	* gfortran.dg/gomp/append_args-4.f90: Likewise.
	* gfortran.dg/gomp/interop-1.f90: Likewise.
	* gfortran.dg/gomp/interop-2.f90: Likewise.
	* gfortran.dg/gomp/interop-3.f90: Likewise.
	* gfortran.dg/gomp/interop-4.f90: Likewise.
	* gfortran.dg/gomp/pr118965-1.f90: New.
	* gfortran.dg/gomp/pr118965-2.f90: New.

(cherry picked from commit aca8155c09001f269a20d6df438fa0e749dd5388)