Using Spanish verb venir a + infinitive to indicate approximation/end of a process (perífrasis verbal)

In Spanish, to indicate either an approximation or the end of a process we can use this verbal structure:

Venir a to express approximation

We can see in the examples above that the speakers are talking about something approximate ( "more or less" of something). 

Venir a to express the end of a process

In these examples we can infer that something was going on and as a result the action expressed with venir a + infinitive occurred.