Runtime overloaded functions

Unlike https://github.com/rokucommunity/brighterscript/issues/444 which is only at typetime/compiletime, this proposal is to implement actual transpile support.

Given this source code:

function getPrice(price as integer)
    return price
end function 
function getPrice(price as string)
    return toNumber(price)
end function 

function main()
    price = getPrice(100)
    price = getPrice("200")
    someNum = 100 as dynamic 
    price = getPrice(someNum)
end function

It would transpile to:

function getPrice_1(price as integer)
    return price
end function 
function getPrice_2(price as string)
    return toNumber(price)
end function 

function getPrice(price as dynamic)
    if type(price) = "number"
        return getPrice_1(price)
    else
        return getPrice_2(price)
    end if
end function

function main()
    price = getPrice_1(100)
    price = getPrice_2("200")
    someNum = 100 as dynamic 
    price = getPrice_safe(someNum)
end function

Limitations:

1. We probably can't support complex types here (like interfaces) without significant runtime effort to determine the type. So should be limited to only simple things (like primitives, or perhaps specific node types since it's a single check)
2. anytime we don't know the type, it would fall into the safe generic one, which will be more expensive than the type-specific overload. However, this is up to the development team to enforce string typing to get the performance benefits of this approach.

Start by reading the related issue #444 and tracing the compiler's transpilation entry points; this issue names no files or tests. Done means supporting the proposed runtime overload transformation, including type-specific dispatch and a safe fallback for unknown types, within the stated type limitations.