fix(ssa): Consider shl and shr to have side effects

compiler/noirc_evaluator/src/ssa/ir/instruction.rs

@@ -460,16 +460,21 @@ impl Instruction {
                 BinaryOp::Div | BinaryOp::Mod => {
                     dfg.get_numeric_constant(binary.rhs).is_none_or(|c| c.is_zero())
                 }
+                BinaryOp::Shl | BinaryOp::Shr => {
+                    // Bit-shifts which are known to be by a number of bits less than the bit size of the type have no side effects.
+                    dfg.get_numeric_constant(binary.rhs).is_none_or(|c| {
+                        let typ = dfg.type_of_value(binary.lhs);
+                        c >= typ.bit_size().into()
+                    })
+                }
                 BinaryOp::Add { unchecked: true }
                 | BinaryOp::Sub { unchecked: true }
                 | BinaryOp::Mul { unchecked: true }
                 | BinaryOp::Eq
                 | BinaryOp::Lt
                 | BinaryOp::And
                 | BinaryOp::Or
-                | BinaryOp::Xor
-                | BinaryOp::Shl
-                | BinaryOp::Shr => false,
+                | BinaryOp::Xor => false,
             },
 
             // These don't have side effects

test_programs/execution_success/regression_9544/Nargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "regression_9544"
+type = "bin"
+authors = [""]
+
+[dependencies]

test_programs/execution_success/regression_9544/Prover.toml

@@ -0,0 +1,2 @@
+c = 8483479640938442498
+return = 5

test_programs/execution_success/regression_9544/src/main.nr

@@ -0,0 +1,15 @@
+fn main(c: u64) -> pub u64 {
+    if c == 1 {
+        if c == 2 {
+            c >> c
+        } else {
+            3
+        }
+    } else {
+        if c == 4 {
+            c >> c
+        } else {
+            5
+        }
+    }
+}