RFR: 8294538: missing is_unloading() check in SharedRuntime::fixup_callers_callsite()

[Dean Long]

This change adds a missing is_unloading() check for the callee in SharedRuntime::fixup_callers_callsite() and removes from_compiled_entry_no_trampoline() because it is no longer used.

-------------

Commit messages:
 - check callee->is_unloading in fixup_callers_callsite

Changes: https://git.openjdk.org/jdk/pull/10747/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10747&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8294538
  Stats: 22 lines in 3 files changed: 9 ins; 12 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/10747.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10747/head:pull/10747

PR: https://git.openjdk.org/jdk/pull/10747