RFR: 8364141: Remove LockingMode related code from x86

[Coleen Phillimore]

On Wed, 30 Jul 2025 13:17:37 GMT, Fredrik Bredberg <fbredberg at openjdk.org> wrote:

> Since the integration of [JDK-8359437](https://bugs.openjdk.org/browse/JDK-8359437) the `LockingMode` flag can no longer be set by the user, instead it's declared as `const int LockingMode = LM_LIGHTWEIGHT;`. This means that we can now safely remove all `LockingMode` related code from all platforms.
> 
> This PR removes `LockingMode` related code from the **x86** platform.
> 
> When all the `LockingMode` code has been removed from all platforms, we can go on and remove it from shared (non-platform specific) files as well. And finally remove the `LockingMode` variable itself.
> 
> Passes tier1-tier5 with no added problems.

This looks really good.  Thank you for the comment about balanced locking.

src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp line 389:

> 387: // obj: object to lock
> 388: // rax: tmp -- KILLED
> 389: // t  : tmp - cannot be obj nor rax -- KILLED

This same comment is repeated just above so you probably don't need it here.

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Marked as reviewed by coleenp (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/26552#pullrequestreview-3072397438
PR Review Comment: https://git.openjdk.org/jdk/pull/26552#discussion_r2243231761