Add various reduction test-cases with vector length 128.

2019-01-12  Tom de Vries  <tdevries@suse.de>

	* testsuite/libgomp.oacc-c-c++-common/vred2d-128.c: New test.
	* testsuite/libgomp.oacc-fortran/gemm.f90: New test.
	* testsuite/libgomp.oacc-c-c++-common/vector-length-128-10.c: New test.

From-SVN: r267892