Epic: complete support for erasable Checked C syntax

[dtarditi]

We have the following work items to do:

• Create an optional header file: Create header file for erasable Checked C annotations #485
• Create several examples of using the optional header file in code that compiles with and without a compiler that supports Checked C.: Create examples of using the optional header file for erasable syntax. #486
• Create Wiki documentation explaining how to write code using the erasable code. issue Update Wiki documentation on erasable syntax #487.
• Update the Checked C specification to describe the new syntax. Update the Checked C specification to describe erasable syntax #488.

Issue #467 provides some feedback on the overall idea.

[arunkumarbhattar]

I shall work on this