KCL: Cannot pass stdlib functions as values

[adamchalmers]

Here's a simple KCL program.

f = sin

This should work, you should be able to assign stdlib functions to variables. But it doesn't, it fails with an error about sin not being found.

This is because sin and other stdlib functions aren't kept in ProgramMemory, they're looked up in a separate namespace.

You should be able to use stdlib functions as normal KCL values, and pass them around in memory, use them as arguments to functions, etc.

An interesting consequence of this bug is that the MemoryFunction type, for storing Rust functions (i.e. KCL stdlib) in KCL memory, is never actually used.