Different behaviour of overload with return and without return

[Smit-create]

On this python code, overload works fine and prints 3 as the result:

@overload
def add(a: i32) -> i32:
    return a

@overload
def add(a: i32, b: i32) -> i32:
    return a+b

print(add(1, 2))

But the following one fails:

@overload
def add(a: i32):
    print(a)

@overload
def add(a: i32, b: i32):
    print(a+b)

add(1, 2)

ASR:

    throw LFortranException("ASR verify failed: " + error_msg);
LFortranException: ASR verify failed: 92:100: SubroutineCall::m_name cannot point outside of its symbol table

[certik]

I think this might be caused by the fact that we did not yet implement overloading of subroutines. When a subroutine is called, we might not be yet doing the logic with resolving the overload and calling the specific version.

[certik]

The relevant part is:

               (SubroutineCall 1 add () [
                  ((ConstantInteger 1 
                     (Integer 4 []))) 
                  ((ConstantInteger 2 
                     (Integer 4 [])))] ())] 
               Source 
               Public 
               Implementation () .false. .false.), 
         add: 
            (GenericProcedure 
               1 
               add [1 __lpython_overloaded_0__add 1 __lpython_overloaded_1__add] 
               Public), 

where the SubroutineCall must link to the generic subroutine and then provide a specific implementation also.