JDK-8370315 is introducing the possibility of running scenarios concurrently on the same host. We should evaluate which scenario-based tests benefit from running concurrently and switch them accordingly.

Currently the tests using IR-Framework scenarios are the following ones:
compiler/c2/irTests/gc/ReferenceClearTests.java
compiler/c2/irTests/gc/ReferenceRefersToTests.java
compiler/c2/irTests/igvn/TestCleanMemPhi.java
compiler/c2/irTests/scalarReplacement/AllocationMergesTests.java
compiler/c2/irTests/TestFloat16ScalarOperations.java
compiler/c2/irTests/TestPostParseCallDevirtualization.java
compiler/c2/irTests/TestScheduleSmallMethod.java
compiler/c2/irTests/TestVectorizationMismatchedAccess.java🎲
compiler/gcbarriers/TestG1BarrierGeneration.java
compiler/loopopts/superword/ProdRed_Double.java
compiler/loopopts/superword/ProdRed_Float.java
compiler/loopopts/superword/ProdRed_Int.java
compiler/loopopts/superword/RedTest_int.java
compiler/loopopts/superword/RedTest_long.java
compiler/loopopts/superword/SumRed_Double.java
compiler/loopopts/superword/SumRed_Float.java
compiler/loopopts/superword/SumRed_Int.java
compiler/loopopts/superword/SumRed_Long.java
compiler/loopopts/superword/SumRedAbsNeg_Double.java
compiler/loopopts/superword/SumRedAbsNeg_Float.java
compiler/loopopts/superword/SumRedSqrt_Double.java
compiler/loopopts/superword/TestMemorySegment_8359688.java
compiler/loopopts/superword/TestMemorySegment_ReassociateInvariants1.java
compiler/loopopts/superword/TestMemorySegment_ReassociateInvariants2.java
compiler/loopopts/superword/TestMemorySegmentByteSizeLongLoopLimit.java
compiler/loopopts/superword/TestMemorySegmentField.java
compiler/loopopts/superword/TestMemorySegmentFilterSummands.java
compiler/loopopts/TestArrayFillIntrinsic.java
compiler/vectorization/TestFloatConversionsVector.java