Use a lock per UnwindInfoTable object instead of global lock

[eduardo-vp]

Will collect some numbers, in the meantime just checking for CI errors.

[Copilot]

Pull request overview

Updates CoreCLR’s Windows x64 unwind-info publishing to reduce lock contention by moving from a single global lock to a per-UnwindInfoTable lock, improving scalability when multiple code heaps publish unwind data concurrently.

Changes:

• Add a per-table Crst (m_lock) to UnwindInfoTable.
• Use the global lock only for lazy initialization, and use the per-table lock for steady-state add/remove operations.
• Rework the slow-path growth to keep the UnwindInfoTable object stable (swap only the internal pTable array).

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/coreclr/vm/codeman.h	Adds per-UnwindInfoTable lock member.
src/coreclr/vm/codeman.cpp	Switches add/remove synchronization to per-table locking and updates the growth path to swap arrays in-place.

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[Copilot]

Pull request overview

Reduces lock contention in CoreCLR’s Windows x64 unwind info publishing by moving from a single global UnwindInfoTable lock to a per-table lock (one per code range / code heap).

Changes:

• Add a per-UnwindInfoTable Crst to synchronize table updates independently per range.
• Keep the global lock only for lazy initialization of the per-range UnwindInfoTable.
• Change table growth to preserve the UnwindInfoTable object (and its lock) while swapping the internal pTable array.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/coreclr/vm/codeman.h	Adds a per-table Crst member to UnwindInfoTable.
src/coreclr/vm/codeman.cpp	Uses global lock only for lazy init; uses per-table lock for add/remove and resizes by swapping pTable instead of replacing the object.

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