Support reading PE data directly from memory (sections are page aligned)

[valaphee]

At the moment its not possible to load PE data from memory, because sections are located at the virtual_address, not pointer_to_raw_data because of page alignment.

This pr unifies file "address space" and virtual address space, by adding a bool to SectionTable which specifies the location to use.

[philipc]

Do you need this functionality in PeFile, or would it suffice to add something similar such as PeMemory?

Can you add a test for this? It's okay if the test only runs on Windows. This will also give me a better understanding of how you plan to use this.

[valaphee]

Could also be a different struct, but would be nearly identical to PeFile,

Sure, the reason why I added this was to use it with my debugger written in Rust, where I wanted to directly read the executable from memory.

Ideally I would also check how other formats work/how they get loaded into memory.

[philipc]

I had a look at how you are using this in your code, and based on that I agree that it makes sense for this to be an option to PeFile. However, I'm still a bit uncertain as to whether the entire PeFile API will work for this. As such, I want to spend some time looking into this further to satisfy myself. I may not have time to do that for a while though, so apologies in advance for any delay.

For ELF, I think only the PT_LOAD segments specified by the program headers are loaded. You can get a list of the program headers from dl_iterate_phdr, but the rest of the ELF file isn't accessible, so a similar approach can't be used for ElfFile.