False negative: DoubleCheckedLocking.ql cannot detect scenarios with ternary expressions.

**Version**
codeql 2.23.9
**Description of the issue**
When I detect the code like this using java/Likely Bugs/Concurrency/DoubleCheckedLocking.ql, the problem is reported normally:
```java

public class PosCase1 {
private Object instance; // Non-volatile field
public Object getInstance() {
if (instance == null) { // First null check
synchronized (this) { // [REPORTED LINE]
if (instance == null) { // Second null check inside synchronized block
instance = new Object(); // Initialization
}
}
}
return instance; // Return after double-checked locking
}
}
```

However, when ternary expressions are introduced into the code, DoubleCheckedLocking.ql fails to detect the problem:
```java
public class PosCase1_Var1 {
private Object instance; // Non-volatile field
public Object getInstance() {
// Use ternary for outer check, but preserve unsafe pattern
return (instance != null) ? instance : createInstance();
}
private Object createInstance() {
synchronized (this) {
if (instance == null) {
instance = new Object();
}
return instance;
}
}
}
```
These two code snippets are semantically identical, only using a ternary expression with some transformations, which is why DoubleCheckedLocking.ql cannot detect the problem.

從 java/Likely Bugs/Concurrency/DoubleCheckedLocking.ql 開始，並重現 issue 中的兩個 Java 程式碼片段，以比較查詢結果。當查詢回報基於三元運算子的非安全 double-checked locking 情境，同時繼續回報現有的直接模式時，即表示完成。

由索引模型根據 Issue 內容生成。