Add regression tests for compound literal pointers

Four regression tests were added under the “Compound Literals”
section in `tests/driver.sh`

The tests cover:
- char[] compound literal assigned to char* (sum = 200)
- short[] compound literal assigned to short* (sum = 6)
- ternary returning int* with literal in the false branch (true case)
- ternary returning int* selecting the literal branch (false case)

Author: lorettayao

tests/driver.sh

@@ -4759,6 +4759,36 @@ int main() {
 }
 EOF
 
+try_ 200 << EOF
+int main(void) {
+    char *s = (char[]){'A', 'B', 'C', 'D', 'E'};
+    return s[0] + s[1] + s[4]; /* 65 + 66 + 69 */
+}
+EOF
+
+try_ 6 << EOF
+int main(void) {
+    short *s = (short[]){1, 2, 3, 4, 5};
+    return s[0] + s[4];
+}
+EOF
+
+try_ 60 << EOF
+int main(void) {
+    int arr[] = {10, 20, 30, 40, 50};
+    int *selected = 1 ? arr : (int[]){1, 2, 3, 4, 5};
+    return selected[0] + selected[4];
+}
+EOF
+
+try_ 6 << EOF
+int main(void) {
+    int arr[] = {10, 20, 30, 40, 50};
+    int *selected = 0 ? arr : (int[]){1, 2, 3, 4, 5};
+    return selected[0] + selected[4];
+}
+EOF
+
 try_ 120 << EOF
 int main() {
     /* Complex expression with mixed compound literals */