Fix tests under FreeBSD.
check-debug, check-path, and check-system-flags used the following pattern which fails under FreeBSD's /bin/sh
VAR_NAME=value run_test --args
When this is run VAR_NAME
is not exported to run_test
so I changed this pattern to:
VAR_NAME=value
export VAR_NAME
run_test --args
Also added unset
in a few cases where it would/could make a difference.