Issue Description:

Consider following example:

var sum = [1,2]+[3,4]+[5,6]+[7,8]+[9,10]

The compiler will make a error:
Expression was too complex to be solved in reasonable time; consider breaking up the expression into distinct sub-expressions

That is ok.

But, the following example:

 let a=[1,2]
 let b=[3,4]
 let c=[5,6]
 let d=[7,8]
 let e=[9,10]
            
 var sum = a+b+c+d+e

The compiler will NOT make a error and the compiling time will silently take an about a minute.