Add sendmail and switch build to wasixcc

[zebreus]

Add sendmail and switch build to wasixcc

[Copilot]

Pull request overview

This PR transitions the PHP WASIX build system from using direct LLVM/Clang toolchain to the wasixcc wrapper toolchain, and adds the sendmail dependency to support PHP mail functionality through a standard sendmail executable instead of a custom Rust-based WASIX sendmail library.

Changes:

• Replaced manual LLVM 20/21 toolchain setup with wasixcc wrapper toolchain
• Added sendmail/sendmail package dependency to wasmer-32.toml and wasmer-64.toml
• Removed custom wasix_sendmail C integration code and Rust library dependency from ext/standard/mail.c and config.m4
• Removed SMTP configuration parameters from execution scripts

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
wasmer-64.toml	Added sendmail/sendmail dependency
wasmer-32.toml	Added sendmail/sendmail dependency
wasix-execute.sh	Removed SMTP configuration parameters
wasix-execute-eh.sh	Removed SMTP configuration parameters
wasix-configure.sh	Replaced LLVM toolchain with wasixcc, simplified build flags, removed SYSROOT and WASIX_SENDMAIL_LIBS
wasix-configure-eh.sh	Replaced LLVM toolchain with wasixcc, simplified build flags, removed SYSROOT and WASIX_SENDMAIL_LIBS
ext/standard/mail.c	Removed custom wasix_sendmail integration code, now uses standard sendmail_path
ext/standard/config.m4	Removed WASIX_SENDMAIL_LIBS build configuration
.github/workflows/wasix-pr.yaml	Replaced LLVM 21 installation with wasixcc installation action, updated tool version checks

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 12 out of 12 changed files in this pull request and generated 7 comments.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

pipe(pipefd) creates fds without close-on-exec. In a multi-threaded process, concurrent calls to mail()/posix_spawn can cause unrelated children to inherit these pipe fds, potentially preventing EOF delivery and hanging the sendmail process (same class of issue documented in ext/fileinfo/libmagic/compress.c). Prefer creating the pipe with O_CLOEXEC (pipe2) or setting FD_CLOEXEC via fcntl on both ends before spawning.

Suggested change

	#ifdef FD_CLOEXEC
	/* Ensure pipe fds are not unintentionally inherited by unrelated children */
	if (fcntl(pipefd[0], F_SETFD, FD_CLOEXEC) == -1
	|| fcntl(pipefd[1], F_SETFD, FD_CLOEXEC) == -1
	) {
	php_error_docref(NULL, E_WARNING, "Could not set FD_CLOEXEC on pipe for mail delivery: %s", strerror(errno));
	close(pipefd[0]);
	close(pipefd[1]);
	php_mail_free_argv(&args);
	return -1;
	}
	#endif

[Arshia001]

LGTM overall; a few questions, and I find copilot's comment about pinning the wasixcc version valid.

[Arshia001]

LGTM!