Remove the null check from placement new in all modes

Remove the null check from placement new in all modes

gcc/cp/

Remove the null check from placement new in all modes
* init.c (build_new_1): Don't do a null check for
a namespace-scope non-replaceable placement new
in any mode unless -fcheck-new is provided.

testsuite/

Remove the null check from placement new in all modes
* g++.dg/init/pr35878_1.C: Adjust.
* g++.dg/init/pr35878_4.C: New.
* g++.dg/torture/pr48695.C: Adjust.
* g++.dg/tree-ssa/pr31146-2.C: Likewise.
* g++.dg/tree-ssa/pr41428.C: Adjust.

From-SVN: r254694