Delete arrays using `delete[]` and non-arrays using `delete`

Reason

That's what the language requires, and mismatches can lead to resource release errors and/or memory corruption.

Example, bad

void f(int n)
{
    auto p = new X[n];   // n default constructed Xs
    // ...
    delete p;   // error: just delete the object p, rather than delete the array p[]
}

Note

This example not only violates the no naked new rule as in the previous example, it has many more problems.

Enforcement

• Flag mismatched new and delete if they are in the same scope.
• Flag mismatched new and delete if they are in a constructor/destructor pair.