[8u] RFR: 7188942: Remove support of pbuffers in OGL Java2d pipeline

[Vladimir Kempik]

Hello
Please review this backport of 7188942.
After the support for modern Xcode were added to jdk8u, some new tests started failing.
jdk/test/sun/java2d/pipe/hw/RSLAPITest.java is among them.

The testcase fails when ojdk8 is built using Xcode9+, it passes if built with Xcode8
This backport result in RSLAPITest.java passing on any Xcode.

It wasn’t applying cleanly.
This fix passed all the testing in zulu8 for past 4 releases ( since October 2020)

The webrev: http://cr.openjdk.java.net/~vkempik/7188942/webrev.00/

The bug ( can’t be open) :
https://bugs.openjdk.java.net/browse/JDK-7188942

The orignal patch:
https://hg.openjdk.java.net/jdk9/jdk9/jdk/rev/d278d6b53fcb

CC-ing Sergey B. as author of original fix

Thanks in advance, Vladimir.