private void GenInitializer(Symbol sym)
{
if (sym?.Initializer == null)
{
throw new ArgumentException();
}
LLVM.PositionBuilderAtEnd(this.builder, moduleInitializerBlock);
var expr = new ExpressionCompiler(this, builder, moduleInitializerFunction);
var value = expr.Compile(sym.Initializer);
LLVM.BuildStore(builder, value, symbols[sym]);
}