@static_assert(condition) annotation

[dalexeev]

I came up with the idea of the @static_assert(condition) annotation. STANDALONE annotations, unlike statements, can be located anywhere in the script, not necessarily inside a function (for example, _init). Annotations are checked at compile time (in the analyzer), not at runtime (so you will know about the error even before the project starts). Annotation arguments can be any constant expressions.

@static_assert could be used to validate the values of constants, enums and other similar conditions - if you use constants as a config and can change their values, but are worried that you might forget about some condition and set incorrect values. (We should consider making expressions like MyEnum.size() and MyEnum.values().max() constant.)