openmp: Assorted depend/affinity/iterator related fixes [PR100859]

openmp: Assorted depend/affinity/iterator related fixes [PR100859]

The depend-iterator-3.C testcases shows various bugs.

1) tsubst_omp_clauses didn't handle OMP_CLAUSE_AFFINITY (should be
   handled like OMP_CLAUSE_DEPEND)
2) because locators can be arbitrary lvalue expressions, we need
   to allow for C++ array section base (especially when array section
   is just an array reference) FIELD_DECLs, handle them as this->member,
   but don't need to privatize in any way
3) similarly for this as base
4) depend(inout: this) is invalid, but for different reason than the reported
   one, again this is an expression, but not lvalue expression, so that
   should be reported
5) the ctor/dtor cloning in the C++ FE (which is using walk_tree with
   copy_tree_body_r) didn't handle iterators correctly, walk_tree normally
   doesn't walk TREE_PURPOSE of TREE_LIST, and in the iterator case
   that TREE_VEC contains also a BLOCK that needs special handling during
   copy_tree_body_r

2021-06-03  Jakub Jelinek  <jakub@redhat.com>

	PR c++/100859
gcc/
	* tree-inline.c (copy_tree_body_r): Handle iterators on
	OMP_CLAUSE_AFFINITY or OMP_CLAUSE_DEPEND.
gcc/c/
	* c-typeck.c (c_finish_omp_clauses): Move OMP_CLAUSE_AFFINITY
	after depend only cases.
gcc/cp/
	* semantics.c (handle_omp_array_sections_1): For
	OMP_CLAUSE_{AFFINITY,DEPEND} handle FIELD_DECL base using
	finish_non_static_data_member and allow this as base.
	(finish_omp_clauses): Move OMP_CLAUSE_AFFINITY
	after depend only cases.  Let this be diagnosed by !lvalue_p
	case for OMP_CLAUSE_{AFFINITY,DEPEND} and remove useless
	assert.
	* pt.c (tsubst_omp_clauses): Handle OMP_CLAUSE_AFFINITY.
gcc/testsuite/
	* g++.dg/gomp/depend-iterator-3.C: New test.
	* g++.dg/gomp/this-1.C: Don't expect any diagnostics for
	this as base expression of depend array section, expect a different
	error wording for this as depend locator and add testcases
	for affinity clauses.