Hotfix for store_fencei_exec stream located as first stream in program
Created by: silabs-hfegran
Hotfix for the case where the store_fencei_exec stream is the first instruction in the stream (first stream gets its label changed from 0: to main: ) leading to compilation failure - changed jump/branch target to 1: instead. The exact symbol is not important as it is never executed, but it needs to exist for compilation to succeed