prefer_asserts_in_initializer_lists

Assert should be in the initializer list.

The analyzer produces this diagnostic when the body of a constructor begins with one or more assert statements.

The following code produces this diagnostic because the body of the constructor begins with an assert statement:

class C {
  C(int i) {
    assert(i != 0);
  }
}

Move the assert to the initializer list, removing the body if there are only assert statements in it:

class C {
  C(int i) : assert(i != 0);
}

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