[std] disallow some haxe.macro.Context methods on non-macro eval

[kLabz]

Surprisingly (or not?), a good amount of Context methods are perfectly usable outside macro on eval target.

Maybe we'd want to deprecate the usage of some of these in favor of less hacky solutions (getMacroStack for example).

[Simn]

Yes, it would be nice to separate this better. We could have eval.Runtime with all the functions that work in both macro and eval contexts, and then keep only the macro-specific stuff in haxe.macro.Context.

[kLabz]

The distinction is sometimes a bit blurry, like typing expressions etc. work fine on non-macro eval too.

But I do agree separating those and deprecating non-macro use of Context methods in Haxe 5.0 would be nice.