Resolve edge cases in dead code analysis

[IGI-111]

[jjcnn]

One such edge case, regarding aliased imports:

wiz.sw

library;

pub struct Wiz {
    pub wiz: u64,
}

main.sw

script;
// This tests importing other files.

mod wiz;

use wiz::Wiz as WizWiz;

struct Wiz { 
    local_wiz: bool
}

fn main() -> u64 {
    let wiz = WizWiz {
	wiz: 128
    };
    let local_wiz = Wiz { // This should resolve to the locally defined Wiz
	local_wiz: true
    };
    if local_wiz.local_wiz {
	wiz.wiz
    }
    else {
	0
    }
}

The declaration of wiz::Wiz is reported as dead, even thought it is used in main.sw. Also, it's public so it probably shouldn't be reported as dead in the first place.

The above code can be found in test/src/e2e_vm_tests/test_programs/should_pass/language/aliased_imports, which also tests a number of other things regarding aliases. For the time being I'm disabling the dead code analysis for the struct.

[jjcnn]

Same problem in test/src/e2e_vm_tests/test_programs/should_pass/language/import_star_name_clash.