libgomp.c/declare-variant-4-gfx*: Add missing archs + dg-excess-errors

libgomp.c/declare-variant-4-gfx*: Add missing archs + dg-excess-errors

Add missing tests for gfx* context selectors; mark all but the
default-arch declare-variant-4.c with 'dg-excess-errors' to
silence libgomp not-found errors (still passing the
scan-offload-tree-dump check) - or at least causing just
UNRESOLVED errors if the error is
  "built without library support ... consider compiling for
   the associated generic architecture".

In case the multilib is configured, the result will be
an XPASS.

libgomp/ChangeLog:

	* testsuite/libgomp.c/declare-variant-4-gfx10-3-generic.c: Add
	dg-excess-errors to handle possible missing libgomp multi lib.
	* testsuite/libgomp.c/declare-variant-4-gfx1030.c: Likewise.
	* testsuite/libgomp.c/declare-variant-4-gfx1036.c: Likewise.
	* testsuite/libgomp.c/declare-variant-4-gfx11-generic.c: Likewise.
	* testsuite/libgomp.c/declare-variant-4-gfx1100.c: Likewise.
	* testsuite/libgomp.c/declare-variant-4-gfx1103.c: Likewise.
	* testsuite/libgomp.c/declare-variant-4-gfx9-4-generic.c: Likewise.
	* testsuite/libgomp.c/declare-variant-4-gfx9-generic.c: Likewise.
	* testsuite/libgomp.c/declare-variant-4-gfx900.c: Likewise.
	* testsuite/libgomp.c/declare-variant-4-gfx906.c: Likewise.
	* testsuite/libgomp.c/declare-variant-4-gfx908.c: Likewise.
	* testsuite/libgomp.c/declare-variant-4-gfx90a.c: Likewise.
	* testsuite/libgomp.c/declare-variant-4-gfx90c.c: Likewise.
	* testsuite/libgomp.c/declare-variant-4-gfx942.c: Likewise.
	* testsuite/libgomp.c/declare-variant-4-gfx1031.c: New test.
	* testsuite/libgomp.c/declare-variant-4-gfx1032.c: New test.
	* testsuite/libgomp.c/declare-variant-4-gfx1033.c: New test.
	* testsuite/libgomp.c/declare-variant-4-gfx1034.c: New test.
	* testsuite/libgomp.c/declare-variant-4-gfx1035.c: New test.
	* testsuite/libgomp.c/declare-variant-4-gfx1101.c: New test.
	* testsuite/libgomp.c/declare-variant-4-gfx1102.c: New test.
	* testsuite/libgomp.c/declare-variant-4-gfx1150.c: New test.
	* testsuite/libgomp.c/declare-variant-4-gfx1151.c: New test.
	* testsuite/libgomp.c/declare-variant-4-gfx1152.c: New test.
	* testsuite/libgomp.c/declare-variant-4-gfx1153.c: New test.
	* testsuite/libgomp.c/declare-variant-4-gfx902.c: New test.
	* testsuite/libgomp.c/declare-variant-4-gfx904.c: New test.
	* testsuite/libgomp.c/declare-variant-4-gfx909.c: New test.
	* testsuite/libgomp.c/declare-variant-4-gfx950.c: New test.