Windows: Improving common cross-platform code

The Windows-x86 code base can be made more readable and simpler in the following three areas:

- Atomics: Hotspot doesn't make use of existing intrinsics provided by MSVC and Win32, even ones available since Windows XP.
- Exception handling: there is some code repetition which, even if functional, is subpar.
- Frames: we can use the existing os::fetch_frame_from_context to simplify the code and reduce frame parsing logic duplication.