message: Try building constants
diff: use bril_rs as bril;
  use cranelift::frontend::{FunctionBuilder, FunctionBuilderContext, Variable};
  use cranelift::codegen::{ir, isa, settings};
  +use cranelift::codegen::ir::InstBuilder;
  use cranelift::codegen::entity::EntityRef;
  use cranelift::codegen::verifier::verify_function;
  use std::collections::HashMap;
  fn tr_type(typ: &bril::Type) -> ir::Type {
  match typ {
  - bril::Type::Int => ir::types::I32,
  + bril::Type::Int => ir::types::I64,
  bril::Type::Bool => ir::types::B1,
  }
  }
  @@ -62,7 +63,30 @@ fn compile_func(func: bril::Function) {
  builder.declare_var(var, tr_type(typ));
  }
  + // TODO just one block for now...
  let block = builder.create_block();
  + builder.switch_to_block(block);
  +
  + // Insert instructions.
  + for inst in func.instrs {
  + match inst {
  + bril::Code::Instruction(op) => {
  + match op {
  + bril::Instruction::Constant { dest, op, const_type: typ, value } => {
  + let var = vars.get(&dest).unwrap();
  + let val = match value {
  + bril::Literal::Int(i) => builder.ins().iconst(ir::types::I64, i),
  + bril::Literal::Bool(b) => builder.ins().bconst(ir::types::B1, b),
  + };
  + },
  + _ => todo!(),
  + }
  + },
  + _ => todo!(),
  + }
  + }
  +
  + builder.seal_block(block);
  builder.finalize();
  }
  