tests: Allow exec testing of single opcode

4 jobs for big-endian-fixes in 2 minutes and 44 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #582022
debian sid

00:02:44

passed #582025
docker windows 1607
msys2

00:01:11

passed #582023
docker windows 1607
vs2017 amd64

00:01:12

passed #582024
docker windows 1607
vs2017 x86

00:01:15