When committing fails we will see a warning in NON_PRODUCT. This should be improved:
- warning should be done using UL
- we should assert if we try to commit something outside an existing allocation

This work can follow JDK-8255978, and ideally should follow the same error handling pattern done there: check the mapping using the new helper functions (os::win32::find_mapping()) and assert if our notion of allocation does not match reality; also log if commit fails.