Adds the ability to define enums inside ChaiScript with syntax:
  enum Color { Red, Green, Blue }
  enum Priority { Low = 10, Medium = 20, High = 30 }

Enum values are strongly typed Dynamic_Objects accessed via :: syntax
(e.g. Color::Red). A validating constructor from int is registered that
rejects values outside the defined range. Functions declared with an enum
parameter type (e.g. def fun(Color val)) correctly reject plain integers,
enforcing type safety at the dispatch level.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Remove Enum_Access AST node type — reuse Id_AST_Node for enum value
lookups by combining "EnumName::ValueName" at parse time. Replace
std::set with std::vector for valid value tracking (enums are small).
Net removal of ~18 lines.

Requested by @lefticus in PR ChaiScript#679 review.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Requested by @lefticus in PR ChaiScript#679 review.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

…num-support

Merge upstream/develop (including namespace support from ChaiScript#552, WASM
support from ChaiScript#678, and grammar diagrams from ChaiScript#628) and adapt enum
implementation for compatibility with the :: dot-access semantics.

Enum values are now stored as attributes on a container Dynamic_Object,
aligning with how namespaces store members. The from_int() factory
method replaces direct constructor syntax since a name cannot be both
a global object (for :: access) and a callable constructor.

Requested by @lefticus in PR ChaiScript#679 review.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

…ng type

- Change syntax from `enum` to `enum class` (only strongly-typed enums)
- Support optional underlying type: `enum class Flags : char { ... }`
  (defaults to `int` when omitted)
- Replace `from_int` with a constructor named after the enum type,
  accessed as `Color::Color(1)` — the underlying type is no longer
  hardcoded to int
- Use Boxed_Number for type-generic value storage and comparison
- to_underlying now returns the actual underlying type

Note: `Color(1)` syntax is not possible because ChaiScript's global
objects shadow functions with the same name; `Color::Color(1)` is the
C++-consistent alternative.

Requested by @lefticus in PR ChaiScript#679 review.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

Requested by @lefticus in PR ChaiScript#679 review.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

…ation

Add enum production rules to the EBNF grammar. Add comprehensive enum
section to the cheatsheet covering syntax, explicit values, underlying
type specification, construction, to_underlying, comparison, type-safe
dispatch, and switch usage. Document that the underlying type must be a
numeric type (string cannot be used) and list all available types.

Requested by @lefticus in PR ChaiScript#679 review.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>