Fix oci8/pdo_oci random test failures when run in parallel

[mvorisek]

fix #8348 (comment)

I seached CREATE in the ext/oci8/tests directory and almost all tests are conflicting (using the same name). This solution using a CONFLICTS file seems to be used also in other ext tests directories like mysql.

[cmb69]

Thank you!

[mvorisek]

One off topic question, why are the tests /w opcache by about 40% slower?

I would expect them to be about the same or faster.

[cmb69]

One off topic question, why are the tests /w opcache by about 40% slower?

I assume that is due to OPcache overhead, which may not pay off for a single test run.

[mvorisek]

But that is brutal! Someone should probably look into the startup opcache delay, as the tests are usually very simple, so there should be minimal per initial code analysis overhead.