Using -runs consistently in libFuzzer tests

Timeouts when running tests are annoying,
but for many libFuzzer tests lacking -runs argument that’s an expected failure mode.
Should we go through all the tests making sure that -runs is supplied?

Motivation: https://bugs.llvm.org/show_bug.cgi?id=38034

This sounds reasonable to me. Some tests could probably use a seed as well.

Not sure. My answer would depend on a particular test.

for some tests -runs should not be required.

Not sure. My answer would depend on a particular test.

for some tests -runs should not be required.

For which ones?
My point is that failing tests should not hang, and while -runs should not be requires when the test passes,
it comes in handy when it does not.