RFR: JDK-8304867: Explicitly disable dtrace for ppc builds [v2]

[Matthias Baesken]

> Currently the support for the JVM feature 'dtrace' is not implemented in the HS codebase on ppc, so we should disable it in the jvm-features make detection as well. Otherwise we could run into building with dtrace feature support if e.g. the 'dtrace' tool and related header(s) are available on the build machine.
> 
> Probably the same is true for the s390x platform, see
> https://github.com/openjdk/jdk/blob/0deb648985b018653ccdaf193dc13b3cf21c088a/src/hotspot/cpu/s390/c1_LIRAssembler_s390.cpp#L226
> but I only looked a bit more into ppc.

Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:

  Adjust output for dtrace checking

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/13173/files
  - new: https://git.openjdk.org/jdk/pull/13173/files/8273b6b8..e417fad5

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13173&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13173&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/13173.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13173/head:pull/13173

PR: https://git.openjdk.org/jdk/pull/13173