Correct spacing around new and delete.

This fixes llvm.org/PR14913.

Before:  A *a = new(placement) A;
After:   A *a = new (placement) A;

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172212 91177308-0d34-0410-b5e6-96231b3b80d8