[11u backport] RFR(M): 8213754: PPC64: Add Intrinsics for isDigit/isLowerCase/isUpperCase/isWhitespace

[Gustavo Romero]

Hi,

Could the following backport to 11u be reviewed, please?

Bug     : https://bugs.openjdk.java.net/browse/JDK-8213754
Change  : http://hg.openjdk.java.net/jdk/jdk/rev/7384e00d5860
Backport: http://cr.openjdk.java.net/~gromero/8213754_jdk11u/v1/

It adds 4 intrinsics that use instructions introduced by POWER9 in order to
speed up methods isDigit, isLowerCase, isUpperCase, and isWhitespace.

The change is mostly PPC64-only but it does touch shared code, for
instance, in order to adapt the methods in question to be properly
intrinsified. It also needs an additional change [0], since one Graal
test has to be adapted (a separated RFR to backport [0] was sent to [1]).

The change applies almost cleanly: only a small tweak is necessary because
the hunk for ppc.ad file relies on some absent text in the 11u code around
the change to be applied. That absent text is related to the Superword
feature (a non-related feature), which is not backported yet to 11u.

This backport was tested on POWER8 and POWER9 and no regressions were
observed.

This backport was also tested on x86_64 with
./test/hotspot/jtreg/compiler/{c1,c2,intrinsics} plus
./test/hotspot/jtreg/compiler/graalunit (with Graal compiler enabled) with
change 8215317 [0] applied and no regressions were observed too.

Thank you.

Best regards,
Gustavo

[0] http://cr.openjdk.java.net/~gromero/8215317_jdk11u/v1/
[1] https://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2019-January/032266.html