RFR: 8266504: Remove leftovers from BarrierSetAssemblerC1

[Roman Kennke]

Earlier incarnation of Shenandoah required resolve() and naming of runtime calls. We can safely remove a bunch of obsolete code from BarrierSetC1.

Testing:
 - [x] hotspot_gc_shenandoah
 - [x] tier1
 - [x] tier2

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Commit messages:
 - 8266504: Remove leftovers from BarrierSetAssemblerC1

Changes: https://git.openjdk.java.net/jdk/pull/3857/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3857&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8266504
  Stats: 42 lines in 7 files changed: 0 ins; 38 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3857.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3857/head:pull/3857

PR: https://git.openjdk.java.net/jdk/pull/3857