Access specifiers for class members and base classes

[llvm-beanz]

Is your feature request related to a problem? Please describe.
To increase compatibility with C++ and to allow more traditional OO design patterns, HLSL should support the public, private and protected access specifiers for class members and base classes.

HLSL already uses private access for builtin data types to hide members that we don't want users poking at directly, we should give this feature to users to allow them the same capabilities.