RFR: 8295953: Use enhanced-for cycle instead of Enumeration in sun.security

[Andrey Turbanov]

java.util.Enumeration is a legacy interface from java 1.0.
There are a few places with cycles which use it to iterate over collections. We can replace this manual cycle with enchanced-for, which is shorter and easier to read.

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Commit messages:
 - [PATCH] Use enhanced-for cycle instead of Enumeration in sun.security

Changes: https://git.openjdk.org/jdk/pull/10734/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10734&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8295953
  Stats: 32 lines in 6 files changed: 0 ins; 18 del; 14 mod
  Patch: https://git.openjdk.org/jdk/pull/10734.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10734/head:pull/10734

PR: https://git.openjdk.org/jdk/pull/10734