RFR: 8295379: ProblemList java/lang/Float/Binary16Conversion.java in Xcomp mode on x64

[Daniel D. Daugherty]

A trivial fix to ProblemList a couple of tests in -Xcomp mode on generic-x64:

[JDK-8295379](https://bugs.openjdk.org/browse/JDK-8295379) ProblemList java/lang/Float/Binary16Conversion.java in Xcomp mode on x64
[JDK-8295380](https://bugs.openjdk.org/browse/JDK-8295380) ProblemList gc/cslocker/TestCSLocker.java in Xcomp mode on x64

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Commit messages:
 - 8295380: ProblemList gc/cslocker/TestCSLocker.java in Xcomp mode on x64
 - 8295379: ProblemList java/lang/Float/Binary16Conversion.java in Xcomp mode on x64

Changes: https://git.openjdk.org/jdk/pull/10719/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10719&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8295379
  Stats: 2 lines in 2 files changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/10719.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10719/head:pull/10719

PR: https://git.openjdk.org/jdk/pull/10719