Cleanup: Remove dead code in codegen

[mjm918]

Description

There are unused functions and fields in the codegen module that should be removed or utilized.

Warnings

warning: field `symbols` is never read
   --> namlc/src/codegen/cranelift/mod.rs:124:5
    |
121 | pub struct JitCompiler<'a> {
    |            ----------- field in this struct
...
124 |     symbols: &'a SymbolTable,

warning: function `call_array_get` is never used
    --> namlc/src/codegen/cranelift/mod.rs:5388:4

warning: function `call_map_get` is never used
    --> namlc/src/codegen/cranelift/mod.rs:5695:4

Action Items

• Remove or use symbols field in JitCompiler
• Remove or use call_array_get function
• Remove or use call_map_get function

Priority

Low - these are warnings, not bugs.

[mjm918]

Removed unused code:

• Removed symbols field from JitCompiler struct
• Removed symbols parameter from JitCompiler::new and compile_and_run
• Removed unused call_array_get function
• Removed unused call_map_get function

Build now completes with no warnings.