RFR: 8295457: Make the signatures of write barrier methods consistent [v2]

[Zixian Cai]

> Currently, the signatures for various write barrier related methods are inconsistent and can be a bit confusing. Let's take x86 as an example.
> 
> The `store_at` of `BarrierSetAssembler` uses `dst` and `val`, and similarly for `oop_store_at` of `CardTableBarrierSetAssembler`.
> 
> https://github.com/openjdk/jdk/blob/358ac07255cc640cbcb9b0df5302d97891a34087/src/hotspot/cpu/x86/gc/shared/barrierSetAssembler_x86.hpp#L50
> 
> https://github.com/openjdk/jdk/blob/358ac07255cc640cbcb9b0df5302d97891a34087/src/hotspot/cpu/x86/gc/shared/cardTableBarrierSetAssembler_x86.hpp#L38
> 
> However, `access_store_at` and `store_heap_oop` of `MacroAssembler` use `dst` and `src`, presumably copied from `access_load_at` and `load_heap_oop` respectively.
> 
> https://github.com/openjdk/jdk/blob/358ac07255cc640cbcb9b0df5302d97891a34087/src/hotspot/cpu/x86/macroAssembler_x86.hpp#L355
> 
> https://github.com/openjdk/jdk/blob/358ac07255cc640cbcb9b0df5302d97891a34087/src/hotspot/cpu/x86/macroAssembler_x86.hpp#L362
> 
> This PR cleans up the signature of write barrier methods across affected architectures, hopefully making them less confusing.

Zixian Cai has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains three commits:

 - Merge remote-tracking branch 'origin/master' into store_heap_oop
 - Fix store_heap_oop
 - Fix access_store_at

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Changes: https://git.openjdk.org/jdk/pull/10739/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10739&range=01
  Stats: 23 lines in 7 files changed: 0 ins; 0 del; 23 mod
  Patch: https://git.openjdk.org/jdk/pull/10739.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10739/head:pull/10739

PR: https://git.openjdk.org/jdk/pull/10739