openmp: Add shared to parallel for linear on parallel master taskloop simd [PR99928]

I forgot to add default(none) and defaultmap(none) wherever possible on the
testcases to make sure none of the required clauses are added implicitly (because
in that case it doesn't work with these none arguments of those default* clauses
or works differently with other default* settings.

And that revealed we didn't add shared on parallel for linear clause
on parallel master taskloop simd, so this patch fixes that too.

2021-05-29  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/99928
	* gimplify.c (gimplify_scan_omp_clauses): For taskloop simd
	combined with parallel, make sure to add shared clause to
	parallel for explicit linear clause.

	* c-c++-common/gomp/pr99928-1.c: Add default(none) to constructs
	combined with parallel, teams or taskloop and defaultmap(none)
	to constructs combined with target.
	* c-c++-common/gomp/pr99928-2.c: Likewise.
	* c-c++-common/gomp/pr99928-3.c: Likewise.
	* c-c++-common/gomp/pr99928-4.c: Likewise.
	* c-c++-common/gomp/pr99928-5.c: Likewise.
	* c-c++-common/gomp/pr99928-6.c: Likewise.
	* c-c++-common/gomp/pr99928-7.c: Likewise.
	* c-c++-common/gomp/pr99928-8.c: Likewise.
	* c-c++-common/gomp/pr99928-9.c: Likewise.
	* c-c++-common/gomp/pr99928-10.c: Likewise.
	* c-c++-common/gomp/pr99928-13.c: Likewise.
	* c-c++-common/gomp/pr99928-14.c: Likewise.