fix testsuite/g++.dg/init/new26.C for C++-14 and later

This test fails during the execution on VxWorks 7 when using
C++-14 and C++-17.


for  gcc/testsuite/ChangeLog

	* g++.dg/init/new26.C: Fix overriding of the delete operator
	for c++14 profile.