Ignore checkcast in Java 21 type switch

[gtoison]

Repurposed SwitchHandler to keep track of the InvokeDynamic corresponding to a Java 21 type switch.

We detect that the switch uses the object type by looking for a typeSwitch invocation.
Then we ignore the checkcast for each of the switch's target PC + 1

    11  invokedynamic 0 typeSwitch(java.lang.Object, int) : int [13]
    16  lookupswitch default: 72
          case 0: 44
          case 1: 58
    44  aload_2
    45  checkcast Issue2782$Impl1 [17]
    48  astore 4 [impl1]
    50  aload 4 [impl1]
    52  invokevirtual Issue2782$Impl1.helloFromImpl1() : Issue2782$MyInterface [19]
    55  goto 82
    58  aload_2
    59  checkcast Issue2782$Impl2 [23]
    62  astore 5 [impl2]
    64  aload 5 [impl2]
    66  invokevirtual Issue2782$Impl2.helloFromImpl2() : Issue2782$MyInterface [25]
    69  goto 82
    72  new java.lang.IllegalArgumentException [28]

I have removed the sample provided by @robinjhector in #2782 so we don't have to compile Java 21 code because it doesn't seem to work for now. Instead I'm using the compiled .class files directly.

Update: this PR effectively upgrades the build to JDK 21 (from 17 AND 21) since we now use Java 21 language features in bug samples

This PR enables the compilation of bug samples using Java 21 language features when running on JDK 21 or above

[ThrawnCA]

This is essentially "if not...else" which is a double negative. Perhaps refactor to "if null then return false".

[gtoison]

Yes, I have made the change

[ThrawnCA]

Couldn't this be a second foreach loop?

[gtoison]

I have made the change

[hazendaz]

Am I missing where jdk 21 only is required? I don't see any new imports and tests seem to all indicate only run with jdk 21 so I think jdk 17 is still allowed?

Also this is still in Draft so I presume you will remove it from draft once its ready to be merged.

[gtoison]

I've highligted the part where a JDK 21 is required: we're building bug samples using Java 21 language features.
Ideally the samples would be compiled using various JDK, because the bytecode might be different.

[gtoison]

I have reverted the change to continue building on JDK 17 and 21, the bug samples using java 21 langage features are not built when running on JDK 17 (and the correspoding tests are skipped)

[JuditKnoll]

If Java 21 is needed for all the test to run, I think it's better if we stuck to this version for the release.