Fix php-wasm popen stream leaks

[chubes4]

Summary

• Close wasm popen() read-mode output with regular file-stream semantics because the shim buffers process output into /tmp/popen_output, not a real process pipe.
• Apply the same close semantics to the php_exec() paths used by exec(), shell_exec(), system(), and passthru().
• Add regression coverage for repeated process-output calls without leaked Emscripten FS streams.
• Include focused PHP 8.3 Node.js JSPI and Asyncify builds used by the regression test.

Fixes #3678.

Testing

• npm exec nx -- run php-wasm-node:test-group-1-asyncify --testNamePattern="closes read-mode process output streams"
• npm exec nx -- run php-wasm-node:test-group-1-jspi --testNamePattern="closes read-mode process output streams"
• npm exec nx -- run php-wasm-node:lint
• npm exec nx -- run php-wasm-node:typecheck
• prettier --check packages/php-wasm/node/src/test/php-part-1.spec.ts packages/php-wasm/supported-php-versions.mjs

Artifact scope

• PHP 8.3 Node.js Asyncify and JSPI artifacts are included so the regression test executes against the repaired runtime.
• Other PHP versions and web artifacts remain unchanged; they will inherit the source fix when rebuilt.

AI assistance

• OpenCode with OpenAI gpt-5.5 was used for initial root-cause analysis and patch/test drafting.
• OpenCode with OpenAI gpt-5.6-sol was used to review the implementation, diagnose the GitHub diff timeout, narrow the generated artifact scope, and verify the repaired comparison. Chris reviewed and directed the work.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

This PR fixes file descriptor/stream leaks in the php-wasm popen() read-mode shim by switching to regular file closing semantics, and adds regression tests to ensure repeated process-output APIs don’t leak /tmp/popen_output streams.

Changes:

• Switch read-mode process-output streams from pipe-backed streams to file-backed streams (closing via fclose() semantics).
• Apply the same behavior to exec() / shell_exec() / system() paths that consume the same shim.
• Add a regression test that runs 100 iterations per API and asserts no increase in open /tmp/popen_output streams (for PHP 8.3 builds).

Reviewed changes

Copilot reviewed 3 out of 7 changed files in this pull request and generated 3 comments.

File	Description
packages/php-wasm/node/src/test/php-part-1.spec.ts	Adds regression coverage asserting no /tmp/popen_output stream leaks across repeated calls.
packages/php-wasm/compile/php/php_wasm.c	Switches wasm_php_exec stream creation from pipe semantics to file semantics.
packages/php-wasm/compile/php/Dockerfile	Patches upstream PHP sources so read-mode popen/exec use file semantics in wasm builds.

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[brandonpayton]

Weird... GitHub is showing zero changes for this PR. I'm updating it to the latest from trunk to see whether it resets anything.

[brandonpayton]

When I click the "Files Changed" tab, I've gotten different changed file counts this evening. I may just checkout the PR branch and review locally based on a Git diff.

[chubes4]

I think there was a glitch here, because I also saw no changes after your previous comment, then it was showing a large diff. After my last push it seems back to normal on my end.