Refactor warning mechanisms

[mingweishih]

The PR refactors the warning mechanisms based on #67. More specifically, the PR does the following:

• Make the warning messages consistent
  • Use the backtick (`) and the single quote mark (') to quote the keyword/name.
  • Use same format for previous warning messages
• Provide options to existing warnings
  • Add -Wnon-portable-type, -Wsigned-size-or-count, and -Wunsupported-allow options
  • -Wnon-portable-type and -Wsigned-size-or-count are turned on by default, which retains the existing behavior.
• Explicitly error out the use of allow syntax in trusted functions.
• Add more test cases

Signed-off-by: Ming-Wei Shih mishih@microsoft.com

[oe-ci-robot]

Hi @mingweishih. Thanks for your PR.

I'm waiting for a openenclave member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[mingweishih]

/ok-to-test

[oe-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: anakrish, mingweishih

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Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/openenclave/oeedger8r-cpp/blob/master/OWNERS)~~ [anakrish,mingweishih] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment

[oe-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: anakrish, mingweishih

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/openenclave/oeedger8r-cpp/blob/master/OWNERS)~~ [anakrish,mingweishih] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment