RFR: 8375536: PPC64: Implement special MachNodes for floating point CMove

[David Briemann]

Adds the following mach nodes:
match(Set dst (CMoveF (Binary cop (CmpF op1 op2)) (Binary src1 src2)));
match(Set dst (CMoveD (Binary cop (CmpD op1 op2)) (Binary src1 src2)));
match(Set dst (CMoveF (Binary cop (CmpD op1 op2)) (Binary src1 src2)));
match(Set dst (CMoveD (Binary cop (CmpF op1 op2)) (Binary src1 src2)));

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Commit messages:
 - 8375536: PPC64: Implement special MachNodes for floating point CMove

Changes: https://git.openjdk.org/jdk/pull/29281/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29281&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8375536
  Stats: 107 lines in 6 files changed: 100 ins; 5 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/29281.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29281/head:pull/29281

PR: https://git.openjdk.org/jdk/pull/29281