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() and shell_exec() paths that consume the same wasm popen() shim.
• Add regression coverage for repeated popen(), exec(), shell_exec(), and system() calls.
• Update the committed PHP 8.3 node JSPI/Asyncify wasm binaries used by the regression test while leaving generated JS unchanged.

Fixes #3678.

Testing

• node packages/php-wasm/compile/build.js --PLATFORM=node --PHP_VERSION=8.3.31 --WITH_JSPI=yes
• node packages/php-wasm/compile/build.js --PLATFORM=node --PHP_VERSION=8.3.30
• PHP=8.3 npm exec nx -- run php-wasm-node:test-group-1-jspi --testNamePattern=\"closes read-mode process output streams\"
• PHP=8.3 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:lint
• npm exec nx -- run php-wasm-node:typecheck

Notes

• Generated JS files were restored after rebuilding to avoid generated JS churn; the tests pass against the updated committed wasm binaries.
• The Asyncify node build currently points at 8_3_30, while JSPI points at 8_3_31, so the rebuilt wasm artifacts preserve those existing paths.

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (openai/gpt-5.5)
• Used for: Root cause analysis, patch drafting, regression test drafting, and local verification. 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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