ignore pointer size tests

As of JVM 12 and later it is no longer possible to cast away the
``final`` modifier using reflection so the ``forece{32,64}Bit``
helpers error out with an exception:

    Tests run: 34, Failures: 0, Errors: 2, Skipped: 1, Time elapsed: 0.052 sec <<< FAILURE! - in org.bridj.DemanglingTest
    testIntVsPointer_32bits(org.bridj.DemanglingTest)  Time elapsed: 0.006 sec  <<< ERROR!
    java.lang.RuntimeException: java.lang.NoSuchFieldException: modifiers
        at java.base/java.lang.Class.getDeclaredField(Class.java:2610)
        at org.bridj.util.ReflectionUtils.makeFieldWritable(ReflectionUtils.java:42)
        at org.bridj.util.PlatformTestUtils.forcePointerSize(PlatformTestUtils.java:22)
        at org.bridj.util.PlatformTestUtils.force32Bits(PlatformTestUtils.java:30)
        at org.bridj.DemanglingTest.testIntVsPointer_32bits(DemanglingTest.java:553)

    testIntVsPointer_64bits(org.bridj.DemanglingTest)  Time elapsed: 0.001 sec  <<< ERROR!
    java.lang.RuntimeException: java.lang.NoSuchFieldException: modifiers
        at java.base/java.lang.Class.getDeclaredField(Class.java:2610)
        at org.bridj.util.ReflectionUtils.makeFieldWritable(ReflectionUtils.java:42)
        at org.bridj.util.PlatformTestUtils.forcePointerSize(PlatformTestUtils.java:22)
        at org.bridj.util.PlatformTestUtils.force64Bits(PlatformTestUtils.java:33)
        at org.bridj.DemanglingTest.testIntVsPointer_64bits(DemanglingTest.java:566)

Disable those tests until the functionality can be restored.

References:

    - https://bugs.openjdk.java.net/browse/JDK-8210522
    - https://stackoverflow.com/a/56043252/7321177

Signed-off-by: Philipp Gesang <[email protected]>

src/test/java/org/bridj/DemanglingTest.java

@@ -549,6 +549,7 @@ static void checkSymbol(String demanglerName, String str, MemberRef symbol, Type
     }
 
     @Test
+    @Ignore("Can’t work in JVM 12+: https://bugs.openjdk.org/browse/JDK-8210522")
     public void testIntVsPointer_32bits() throws NoSuchFieldException, IllegalArgumentException, IllegalAccessException {
         force32Bits();
 
@@ -562,6 +563,7 @@ public void testIntVsPointer_32bits() throws NoSuchFieldException, IllegalArgume
     }
 
     @Test
+    @Ignore("Can’t work in JVM 12+: https://bugs.openjdk.org/browse/JDK-8210522")
     public void testIntVsPointer_64bits() throws NoSuchFieldException, IllegalArgumentException, IllegalAccessException {
         force64Bits();