Refactor array access for the interpreter.

Adds GetWithoutChecks and SetWithoutChecks methods in PrimitiveArray and use
them in the interpreter. Updates Get and Set methods to rely on them and adds
some DCHECK to control exception flow.

Renames IsValidIndex into CheckIsValidIndex to reflect it can throw an
exception. It's also more consistent with ObjectArray::CheckIsAssignable.

Make ThrowArrayIndexOutOfBoundsException private in Array since it's only used
by Array::CheckIsValidIndex.

Updates DoFilledNewArray to use SetWithoutChecks rather than Set.

Change-Id: I2fd314d77a67cf969843d499b86d04ca7b7a43e6