`GetHeapRanges()` could return two overlapping ranges because it did not
check whether `heap_pointer1` lies within the range returned for
`heap_pointer2`. This could result in a test failure in
`test_find_ranges_in_memory_two_matches` when
`process.FindRangesInMemory()` returned 3 instead of 2.
The patch ensures that `GetHeapRanges()` returns either two
non-overlapping ranges or one range covering both heap pointers.
The issue was probably introduced in #111951
36c2a66968