Create wide fib structure (#541)

<!-- Reviewable:start -->
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/starkware-libs/stwo/541)
<!-- Reviewable:end -->

src/examples/mod.rs

@@ -1 +1,2 @@
 pub mod fibonacci;
+pub mod wide_fibonacci;

src/examples/wide_fibonacci/constraint_eval.rs

@@ -0,0 +1,38 @@
+use super::structs::WideFibComponent;
+use crate::core::air::accumulation::{DomainEvaluationAccumulator, PointEvaluationAccumulator};
+use crate::core::air::{Component, ComponentTrace, Mask};
+use crate::core::backend::CPUBackend;
+use crate::core::circle::CirclePoint;
+use crate::core::fields::qm31::SecureField;
+use crate::core::ColumnVec;
+
+impl Component<CPUBackend> for WideFibComponent {
+    fn max_constraint_log_degree_bound(&self) -> u32 {
+        self.log_size + 1
+    }
+
+    fn trace_log_degree_bounds(&self) -> Vec<u32> {
+        vec![self.log_size; 256]
+    }
+
+    fn mask(&self) -> Mask {
+        Mask(vec![vec![0_usize]; 256])
+    }
+
+    fn evaluate_constraint_quotients_on_domain(
+        &self,
+        _trace: &ComponentTrace<'_, CPUBackend>,
+        _evaluation_accumulator: &mut DomainEvaluationAccumulator<CPUBackend>,
+    ) {
+        unimplemented!("not implemented")
+    }
+
+    fn evaluate_constraint_quotients_at_point(
+        &self,
+        _point: CirclePoint<SecureField>,
+        _mask: &ColumnVec<Vec<SecureField>>,
+        _evaluation_accumulator: &mut PointEvaluationAccumulator,
+    ) {
+        unimplemented!("not implemented")
+    }
+}

src/examples/wide_fibonacci/mod.rs

@@ -0,0 +1,3 @@
+pub mod constraint_eval;
+pub mod structs;
+pub mod trace_gen;

src/examples/wide_fibonacci/structs.rs

@@ -0,0 +1,13 @@
+use crate::core::fields::m31::BaseField;
+
+/// Component that computes fibonacci numbers over 64 columns.
+pub struct WideFibComponent {
+    pub log_size: u32,
+}
+
+// Input for the fibonacci claim.
+#[derive(Debug, Clone, Copy)]
+pub struct Input {
+    pub a: BaseField,
+    pub b: BaseField,
+}

src/examples/wide_fibonacci/trace_gen.rs

@@ -0,0 +1,7 @@
+use super::structs::Input;
+use crate::core::fields::m31::BaseField;
+
+/// Given a private input, write the trace row for the wide Fibonacci example to dst.
+pub fn write_trace_row(_dst: &mut [Vec<BaseField>], _private_input: &Input, _row_offset: usize) {
+    unimplemented!()
+}