RFR: 8305056: Avoid unaligned access in emit_intX methods if not enabled

[Vladimir Kempik]

Please review this change which attempts to eliminate unaligned memory stores generated by emit_int16/32/64 methods on some platforms.

Primary aim is risc-v platform. But I had to change some code in ppc/arm32/x86 to prevent possible perf degradation.

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Commit messages:
 - Fix typo
 - change long to ulong in type convertion
 - Fix includes
 - 8305056: Avoid unaligned access in emit_intX methods if not enabled

Changes: https://git.openjdk.org/jdk/pull/13227/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13227&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8305056
  Stats: 23 lines in 5 files changed: 4 ins; 0 del; 19 mod
  Patch: https://git.openjdk.org/jdk/pull/13227.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13227/head:pull/13227

PR: https://git.openjdk.org/jdk/pull/13227