RFR: 8299191: Unnecessarily global friend functions for relocInfo

[Kim Barrett]

Please review this small cleanup around the relocInfo class.  It declares a
couple of global functions as friends, so they have access to private
constructors and helper functions.  But there is no reason for these functions
to be at global scope.  It is more natural for them to be static factory
functions in relocInfo.

Testing:
mach5 tier1

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Commit messages:
 - make friend functions instead be static members

Changes: https://git.openjdk.org/jdk/pull/11753/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11753&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8299191
  Stats: 23 lines in 3 files changed: 5 ins; 12 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/11753.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11753/head:pull/11753

PR: https://git.openjdk.org/jdk/pull/11753