ECJ fails to report lambda capture of non-effectively final variable in dead code

## ECJ Version:
```bash
Eclipse Compiler for Java(TM) v20250814-1944, 3.43.0, Copyright IBM Corp 2000, 2020. All rights reserved.
```

## Javac Version:
```bash
javac 21.0.8
```

## Description:
When compiling the following Java code, ECJ does not report a compilation error for a lambda expression that captures a loop variable i which is not effectively final, even though such usage is explicitly prohibited. Instead, ECJ only issues a warning about "Dead code" due to the if (false) condition.

In contrast, javac correctly rejects the code with an error.

## Test program:
```java
public class Test {
public static void main(String[] strArr) {
if (false) {
StructContainer[] structArray = new StructContainer[5];
for (int i = 0; i < structArray.length; i++) {
structArray[i] = new StructContainer(() -> i * 10);
}
}else {
}
}
}

class StructContainer {

private final java.util.function.IntSupplier valueSupplier;

public StructContainer(java.util.function.IntSupplier supplier) {
this.valueSupplier = supplier;
}

public int getValue() {
return valueSupplier.getAsInt();
}
}
```

Using javac it will have an error:
```bash
javac Test.java
Test.java:8: error: local variables referenced from a lambda expression must be final or effectively final
structArray[i] = new StructContainer(() -> i * 10);
^
1 error
```

However, ecj only have a warning:
```bash
java -jar ./ecj-4.36M3.jar Test.java
1. WARNING in Test.java (at line 5)
if (false) {
StructContainer[] structArray = new StructContainer[5];
for (int i = 0; i < structArray.length; i++) {
structArray[i] = new StructContainer(() -> i * 10);
}
}else {
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dead code
----------
1 problem (1 warning)
```