add breaking test

zokrates_cli/examples/empty_spread_propagation.zok

@@ -0,0 +1,16 @@
+def func<N>() -> bool:
+    for u32 i in 0..N do
+    endfor
+
+    u64[N] y = [...[0; N-1], 1] // the rhs should *not* be reduced to [1] because the spread is not empty
+    u64 q = 0
+
+    for u32 i in 0..N do
+        q = y[i]
+    endfor
+
+    return true
+
+def main():
+    assert(func::<2>())
+    return