Atomic MemorySegment VarHandle operations fails for element layouts

Atomic operations (such as `VarHandle::getVolatile` and `VarHandle::setVolatile`) fail if derived from a memory layout enclosed in another composite layout (such as a StructLayout).

The reason for this is in `LayoutPath::dereferenceHandle`. Instead of just providing a layout with an alignment of 1, we need to consider both the enclosing layout(s) (transitively) and the current element.

Reproducer:

```
/*
 * @test
 * @run junit TestAtomicVarHandle
 */

import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.Arguments;
import org.junit.jupiter.params.provider.MethodSource;

import java.lang.foreign.Arena;
import java.lang.foreign.MemoryLayout;
import java.lang.invoke.VarHandle;
import java.util.stream.Stream;

import static java.lang.foreign.ValueLayout.JAVA_INT;
import static org.junit.jupiter.api.Assertions.*;

final class TestAtomicVarHandle {

    static final VarHandle INT_VH = JAVA_INT.varHandle();
    static final VarHandle INT_IN_SUPER_ALIGNED_VH = MemoryLayout.structLayout(JAVA_INT.withName("i"))
            .withByteAlignment(32)
            .varHandle(MemoryLayout.PathElement.groupElement("i"));

    @ParameterizedTest
    @MethodSource("methodHandles")
    void test(VarHandle vh, String name) {
        try (Arena arena = Arena.ofConfined()) {
            var segment = arena.allocate(1000, 64);
            int value = (int)vh.getVolatile(segment, 0L);
            assertEquals(0, value);
            vh.set(segment, 0L, 42);
            value = (int)vh.getVolatile(segment, 0L);
            assertEquals(42, value);
        }
    }

    private static Stream<Arguments> methodHandles() {
        return Stream.of(
                Arguments.of(INT_VH, "INT_VH"),
                Arguments.of(INT_IN_SUPER_ALIGNED_VH, "INT_IN_SUPER_ALIGNED_VH")
        );
    }

}


STARTED TestAtomicVarHandle::test '[1] VarHandle[varType=int, coord=[interface java.lang.foreign.MemorySegment, long]], INT_VH'
SUCCESSFUL TestAtomicVarHandle::test '[1] VarHandle[varType=int, coord=[interface java.lang.foreign.MemorySegment, long]], INT_VH'
STARTED TestAtomicVarHandle::test '[2] VarHandle[varType=int, coord=[interface java.lang.foreign.MemorySegment, long]], INT_IN_SUPER_ALIGNED_VH'
java.lang.UnsupportedOperationException: Unsupported access mode for alignment: 1
at java.base/java.lang.invoke.VarHandleSegmentViewBase.newUnsupportedAccessModeForAlignment(VarHandleSegmentViewBase.java:63)
at java.base/java.lang.invoke.VarHandleSegmentAsInts.offsetNonPlain(VarHandleSegmentAsInts.java:88)
at java.base/java.lang.invoke.VarHandleSegmentAsInts.getVolatile(VarHandleSegmentAsInts.java:132)
at TestAtomicVarHandle.test(TestAtomicVarHandle.java:54)

```

Workaround:


```

        static final VarHandle INDEX =
                //HEADER.varHandle(PathElement.groupElement("index")); // Original
                offset(JAVA_INT.varHandle(), HEADER.byteOffset(PathElement.groupElement("index"))); // <-- FIX


    private static VarHandle offset(VarHandle target, long offset) {
        MethodHandle mh = MethodHandles.insertArguments(MH_ADD, 0, offset);
        return MethodHandles.collectCoordinates(target, 1, mh);
    }

    private static final MethodHandle MH_ADD;

    static {
        MethodHandles.Lookup lookup = MethodHandles.lookup();
        try {
            MH_ADD = lookup.findStatic(Long.class, "sum",
                    MethodType.methodType(long.class, long.class, long.class));
        } catch (ReflectiveOperationException e) {
            throw new ExceptionInInitializerError(e);
        }

    }
```