perf(minifier): allocate AST nodes in arena directly

[overlookmotel]

Same as #23709.

Small perf optimizations around AST builder calls.

• AST nodes which end up in Boxes, allocate into the Box as early as possible, to increase chance compiler sees the type can be built directly in arena, rather than built on the stack, and then copied from stack into arena.
• Functions return Box<T> rather than T where the value needs to be boxed anyway. If function is not inlined, this avoids stack allocation + copy.

Also, shorten code where possible by using more specific AstBuilder methods.

[overlookmotel]

• refactor(parser): switch parser to new AstBuilder #23730
• feat(ast): add methods to create primitives to new AstBuilder #23729
• feat(ast): add custom builder methods to AST types #23651
• feat(ast): add AST creation methods to AST types #23650
• refactor(ast): add ast_builder Cargo feature #23649
• perf(transformer/object-rest-spread): reduce iteration #23720
• perf(transformer): allocate AST nodes in arena directly #23711
• perf(parser): allocate AST nodes in arena directly #23712
• perf(minifier): allocate AST nodes in arena directly #23710 👈 (View in Graphite)
• perf(isolated_declarations): allocate AST nodes in arena directly #23709
• refactor(ast): remove AstBuilder::alloc calls #23708
• main

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[codspeed-hq]

Merging this PR will not alter performance

✅ 52 untouched benchmarks
⏩ 19 skipped benchmarks¹

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_{Comparing om/06-21-perf_minifier_allocate_ast_nodes_in_arena_directly (86b4184) with om/06-21-perf_isolated_declarations_allocate_ast_nodes_in_arena_directly (2e9ab4d)}

Footnotes

1. 19 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[Copilot]

Pull request overview

This PR applies small performance-oriented refactors in oxc_minifier to build AST nodes directly into arena-allocated Boxes earlier and to use more specific AstBuilder convenience helpers, reducing stack construction/copies and shortening call sites.

Changes:

• Update AST construction call sites to use alloc_* builder methods directly (e.g., literals, object/block expressions).
• Replace manual BlockStatement boxing patterns with statement_block_with_scope_id / alloc_block_statement helpers.
• Simplify a minifier test to avoid an unnecessary clone_in when the vector is consumed.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
crates/oxc_minifier/tests/ecmascript/array_join.rs	Uses arena-allocating literal/object builders and removes an unnecessary clone_in when constructing the test array AST.
crates/oxc_minifier/src/peephole/remove_dead_code.rs	Swaps Box<BlockStatement> directly using alloc_block_statement, avoiding stack construction + re-allocation for the extracted finalizer block.
crates/oxc_minifier/src/peephole/minimize_statements.rs	Replaces manual block boxing with statement_block_with_scope_id helper for cleaner/faster block statement creation.
crates/oxc_minifier/src/peephole/minimize_if_statement.rs	Uses statement_block_with_scope_id to wrap a consequent in a scoped block without manual allocation/boxing.

[graphite-app]

Merge activity

• Jun 23, 12:59 AM UTC: overlookmotel added this pull request to the Graphite merge queue.
• Jun 23, 1:05 AM UTC: Merged by the Graphite merge queue.