[lworld] RFR: 8255995: templateTable_x86.cpp (TemplateTable::if_acmp) not always do correct null check.

[David Simms]

Testing both pointers at the same time, doesn't account for the case where bits
completely miss each other, resulting in zero as result e.g.

  test(0x10, 0x01) == 0x10 & 0x01 == 0, yet neither are null

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Commit messages:
 - 8255995: templateTable_x86.cpp (TemplateTable::if_acmp) not always do correct null check.

Changes: https://git.openjdk.java.net/valhalla/pull/266/files
 Webrev: https://webrevs.openjdk.java.net/?repo=valhalla&pr=266&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8255995
  Stats: 19 lines in 2 files changed: 18 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/266.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/266/head:pull/266

PR: https://git.openjdk.java.net/valhalla/pull/266