Support building and running on JDK 22 (#1419)

We don't immediately crash on JDK 22 bytecodes, but new bytecode
features have not been tested.

We modify the `TestList` test input to avoid a blowup when running
`SlicerTest.testList`.
openjdk/jdk@b62e774
introduced calls to `String.format` from `Integer.parseInt`, which
dramatically increased the number of reachable methods for the previous
version of this test, which in turn led to very slow performance with
the slicer. Changing the test to use a `List<String>` and string
constants removes this blowup. (Whole-program analysis is fun!)

Fixes #1414

.github/workflows/continuous-integration.yml

@@ -26,6 +26,8 @@ jobs:
             java: 17
           - os: ubuntu-latest
             java: 21
+          - os: ubuntu-latest
+            java: 22
       fail-fast: false
     runs-on: ${{ matrix.os }}
     steps:

core/src/test/java/com/ibm/wala/core/tests/slicer/SlicerTest.java

@@ -1030,7 +1030,7 @@ public void testList()
             .filter(s -> s instanceof NormalStatement && s.getNode().equals(main))
             .collect(Collectors.toList());
     normalsInMain.stream().forEach(System.err::println);
-    assertEquals(7, normalsInMain.size());
+    assertEquals(5, normalsInMain.size());
   }
 
   @Test

core/src/testSubjects/java/slice/TestList.java

@@ -8,10 +8,10 @@ public class TestList {
   static void doNothing(Object o) {}
 
   public static void main(String[] args) {
-    List<Integer> list = new ArrayList<>();
+    List<String> list = new ArrayList<>();
 
-    list.add(2);
-    list.add(3);
+    list.add("hi");
+    list.add("bye");
 
     doNothing(list.get(0));
   }

shrike/src/main/java/com/ibm/wala/shrike/shrikeCT/ClassReader.java

@@ -67,8 +67,8 @@ private void parse() throws InvalidClassFileException {
     if (magic != MAGIC) {
       throw new InvalidClassFileException(offset, "bad magic number: " + magic);
     }
-    // Support class files up through JDK 21 (version 65)
-    if (majorVersion < 45 || majorVersion > 65) {
+    // Support class files up through JDK 22 (version 66)
+    if (majorVersion < 45 || majorVersion > 66) {
       throw new InvalidClassFileException(
           offset, "unknown class file version: " + majorVersion + '.' + minorVersion);
     }