[NFC][scudo] Split ScudoCombinedTest.BasicCombined

Existing implementations took up to 30 minutues to execute on my setup.
Now it's more convenient to debug a single test.

Reviewed By: cryptoad

Differential Revision: https://reviews.llvm.org/D99786

GitOrigin-RevId: f02c6984d76cb42c26524e41814807fdce793487
1 file changed