Added flags parameter to PGTBL CAPTBL_OP_CPY

[evanstella]

Summary of this Pull Request (PR)

Added flags parameter to PGTBL CAPTBL_OP_CPY to edit PTE flags to allow delegation of page access rights. I had to change quite a bit of u32_t to word_t in the CHAL code since 64bit paging on x86_64 uses some high qword bits in the PTE as flags. I think this is also a better design since the x86 CHAL supports both 32bit and 64bit execution modes, but I might be wrong so I am definitely looking for feedback on those edits.

Intent for your PR

Choose one (Mandatory):

• [X] This PR is for a code-review and is intended to get feedback, but not to be pulled yet.
• [ ] This PR is mature, and ready to be integrated into the repo.

Reviewers (Mandatory):

(Specify @<github.com username(s)> of the reviewers. Ex: @user1, @user2) @gparmer @WenyuanShao @betahxy

Code Quality

As part of this pull request, I've considered the following:

Style:

• [X] Comments adhere to the Style Guide (SG)
• [X] Spacing adhere's to the SG
• [X] Naming adhere's to the SG
• [X] All other aspects of the SG are adhered to, or exceptions are justified in this pull request
• [ ] I have run the auto formatter on my code before submitting this PR (see doc/auto_formatter.md for instructions)

Code Craftsmanship:

• [X] I've made an attempt to remove all redundant code
• [X] I've considered ways in which my changes might impact existing code, and cleaned it up
• [X] I've formatted the code in an effort to make it easier to read (proper error handling, function use, etc...)
• [X] I've commented appropriately where code is tricky
• [X] I agree that there is no "throw-away" code, and that code in this PR is of high quality

Testing

I've tested the code using the following test programs (provide list here):

• [ ] micro_booter
• [X] unit_pingpong
• [X] unit_schedtests
• [x] ...sched_ping_pong, sched_crt_tests

[gparmer]

Thanks!