Fix cpp.reshape_strides(), which currently cannot handle inputs that tries to increase the number of dimensions after the reshape.

[pratyai]

Fix the issue with cpp codegen, where it currently cannot handle inputs:

cpp.reshape_strides(Range([(0, 4, 1), (0, 5, 1)]), None, None, [2, 3, 5])

and crashes with an index error.

Also fixes #1690 where RedundantArray was producing a (valid) graph that triggered this.

[acalotoiu]

LGTM -please add the test as discussed

[pratyai]

@acalotoiu,

• The commit ec029bb introduces a test that verifies that there is an exception raised when compiling the transformed graph.
• There are also additional unit tests that covers various cases (I could add even more if we want to be really through).
• The fix commit 2960b9f fixes the compiling problem, but now it verifies that even now the transformed graph is not correct.
• Thanks for insisting on having this case written down. @alexnick83 pointed out earlier that my original input graph (which I started the bug with) had a couple of memlet's ill-defined. So, now I have come up with a slightly different graph to trigger the problem again. Perhaps you would like to see the input graph to confirm that it is indeed a valid SDFG, even if it looks contrived.

    def original_graph_with_redundant_array():
        g = SDFG('prog')
        g.add_array('A', (5, 5), dace.float32)
        g.add_array('b', (1,), dace.float32, transient=True)
        g.add_array('c', (5, 5), dace.float32, transient=True)

        st0 = g.add_state('st0', is_start_block=True)
        st = st0

        # Make a single map that copies A[i, j] to a transient "scalar" b, then copies that out to a transient array
        # c[i, j], then finally back to A[i, j] again.
        A = st.add_access('A')
        en, ex = st.add_map('m0', {'i': '0:1', 'j': '0:1'})
        st.add_memlet_path(A, en, dst_conn='IN_A', memlet=Memlet(expr='A[0:1, 0:1]'))
        b = st.add_access('b')
        st.add_memlet_path(en, b, src_conn='OUT_A', memlet=Memlet(expr='A[i, j] -> b[0]'))
        c = st.add_access('c')
        st.add_memlet_path(b, c, memlet=Memlet(expr='b[0] -> c[i, j]'))
        st.add_memlet_path(c, ex, dst_conn='IN_A', memlet=Memlet(expr='c[i, j] -> A[i, j]'))
        A = st.add_access('A')
        st.add_memlet_path(ex, A, src_conn='OUT_A', memlet=Memlet(expr='A[0:1, 0:1]'))
        st0.fill_scope_connectors()

        g.validate()
        g.compile()
        return g