RFR: 8353188: C1: Clean up x86 backend after 32-bit x86 removal

[Aleksey Shipilev]

Piece-wise cleanup of C1_LIRAssembler_x86, C1_MacroAssembler and related classes. C1 implements the bulk of arch-specific backend there. Major parts of this backend are being removed by #24274, would re-merge after that PR integrates.

Additional testing:
 - [ ] Linux x86_64 server fastdebug, `all`
 - [x] Linux x86_64 server fastdebug, `all` + `-XX:TieredStopAtLevel=1`

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Commit messages:
 - Fix

Changes: https://git.openjdk.org/jdk/pull/24301/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24301&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8353188
  Stats: 1073 lines in 11 files changed: 2 ins; 1026 del; 45 mod
  Patch: https://git.openjdk.org/jdk/pull/24301.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24301/head:pull/24301

PR: https://git.openjdk.org/jdk/pull/24301