RFR: 8299326: LinkResolver::resolve_field resolved_klass cannot be null

[Coleen Phillimore]

Removed the code checking for null and add an assert for the creation of LinkInfo that the resolved_klass can't be null.  Use delegating constructors for LinkInfo.
Tested with tier1-7.

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Commit messages:
 - Remove cast
 - 8299326: LinkResolver::resolve_field resolved_klass cannot be null

Changes: https://git.openjdk.org/jdk/pull/11832/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11832&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8299326
  Stats: 27 lines in 2 files changed: 6 ins; 8 del; 13 mod
  Patch: https://git.openjdk.org/jdk/pull/11832.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11832/head:pull/11832

PR: https://git.openjdk.org/jdk/pull/11832