Deprecate splitWarmAndColdBlocksPhase

[fjeremic]

As discussed in #7049 this phase no longer serves any
purpose since the support for allocating warm and cold blocks at the
code cache level has been removed from the compiler.

Closes: #7049
Signed-off-by: Filip Jeremic fjeremic@ca.ibm.com

[fjeremic]

We can proceed with the review, but before we merge this I will perform several performance runs to ensure removal of this phase has no measurable effect on throughput. As such I'll mark this as WIP until the performance numbers are posted.

[fjeremic]

Finished the performance runs. On DayTrader7 the delta with and without the change is well within the noise range:

----------------------------------------------------------------------------------
Run Name: J8R5-2019-09-17-daytrader7-baseline
----------------------------------------------------------------------------------
Run ID 1 Score: 10238.125
Run ID 2 Score: 10308.9852558543
Run ID 3 Score: 10343.4410480349
Run ID 4 Score: 10311.9458987784
Run ID 5 Score: 10174.5338208409
Run ID 6 Score: 10311.5693112467
Run ID 7 Score: 10283.28125
Run ID 8 Score: 10357.6838235294
Run ID 9 Score: 10217.2038327526
Run ID 10 Score: 10261.0386029412

Average: 10280.7807843978

----------------------------------------------------------------------------------
Run Name: J8R5-2019-09-17-daytrader7-deprecate-split
----------------------------------------------------------------------------------
Run ID 1 Score: 10166.7155172414
Run ID 2 Score: 10283.8362068966
Run ID 3 Score: 10276.79163034
Run ID 4 Score: 10381.719038817
Run ID 5 Score: 10342.7163904236
Run ID 6 Score: 10324.2993907746
Run ID 7 Score: 10342.34375
Run ID 8 Score: 10087.4434782609
Run ID 9 Score: 10239.8160073597
Run ID 10 Score: 10222.4242424242

Average: 10266.8105652538

The data shows that deprecating this phase has no effect on performance.

[fjeremic]

Jenkins test sanity zlinux jdk8

[0xdaryl]

Yay!