dev-libs/expat: Sync with Gentoo

It's from Gentoo commit 5e9e20dcc841d271d30ae5f17638f552ddbb2981.

sdk_container/src/third_party/portage-stable/dev-libs/expat/Manifest

@@ -1,2 +1,3 @@
 DIST expat-2.6.3.tar.xz 485600 BLAKE2B b8e0a0e779f0f136eaca91115cbbcf5a5cca457cab1cca6f8d6141151d19f8ef2dccb41b0e9134459c1e7d99cb2e0b4ce3922d2bd9221002ec43fe9d53a0084a SHA512 e02c4ad88f9d539258aa1c1db71ded7770a8f12c77b5535e5b34f040ae5b1361ef23132f16d96bdb7c096a83acd637a7c907916bdfcc6d5cfb9e35d04020ca0b
 DIST expat-2.6.4.tar.xz 486732 BLAKE2B 70d716722358db8d0acb2c74dbbc9d2362d04a0b856eab6b6d723614b656cf6aad9f6646339e0a32b4151db2e9541439bcb81ec87791e5e6ec0bd36a3ca067cc SHA512 620da34d98524478b445038bf1dd439790fe11169496516425fca922226797835c27549fc5fb825792b516563b24eb922d9ad8f27d20a0229e7ee8cd640dfb25
+DIST expat-2.7.0.tar.xz 493060 BLAKE2B 44567e955b8cf2053665140b3557897c6e0e66c7e2ba5919970d91d55a05bb8db604afa37a441ff0a7abf4472b24b0e1e6c3964c56b4bb55358c000ccdc1459d SHA512 69fb19c2634821b657f550f609d0bcc6e45e9d903072bbc63e9a0bfc92ef7d04c6e1408dd39eb43eaa2951f28ae93dce4f796c9769253f440905db2d5606a4c7

sdk_container/src/third_party/portage-stable/dev-libs/expat/expat-2.7.0.ebuild

@@ -0,0 +1,100 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+AUTOTOOLS_AUTO_DEPEND=no
+inherit autotools multilib-minimal
+
+DESCRIPTION="Stream-oriented XML parser library"
+HOMEPAGE="https://libexpat.github.io/"
+SRC_URI="https://github.com/libexpat/libexpat/releases/download/R_${PV//\./_}/expat-${PV}.tar.xz"
+
+LICENSE="MIT"
+SLOT="0"
+KEYWORDS="~alpha amd64 arm arm64 ~hppa ~loong ~m68k ~mips ppc ppc64 ~riscv ~s390 sparc x86 ~amd64-linux ~x86-linux ~arm64-macos ~ppc-macos ~x64-macos ~x64-solaris"
+IUSE="examples static-libs test unicode"
+RESTRICT="!test? ( test )"
+BDEPEND="unicode? ( ${AUTOTOOLS_DEPEND} )"
+
+DOCS=( README.md )
+
+QA_CONFIG_IMPL_DECL_SKIP=(
+	# https://bugs.gentoo.org/906384
+	arc4random
+	arc4random_buf
+)
+
+src_prepare() {
+	default
+
+	# fix interpreter to be a recent/good shell
+	sed -i -e "1s:/bin/sh:${BASH}:" conftools/get-version.sh || die
+	if use unicode; then
+		cp -R "${S}" "${S}"w || die
+		pushd "${S}"w >/dev/null
+		find -name Makefile.am \
+			-exec sed \
+			-e 's,libexpat\.la,libexpatw.la,' \
+			-e 's,libexpat_la,libexpatw_la,' \
+			-i {} + || die
+		eautoreconf
+		popd >/dev/null
+	fi
+}
+
+multilib_src_configure() {
+	local myconf="$(use_with test tests) $(use_enable static-libs static) --without-docbook"
+
+	mkdir -p "${BUILD_DIR}"w || die
+
+	if use unicode; then
+		pushd "${BUILD_DIR}"w >/dev/null
+		CPPFLAGS="${CPPFLAGS} -DXML_UNICODE" ECONF_SOURCE="${S}"w econf ${myconf}
+		popd >/dev/null
+	fi
+
+	ECONF_SOURCE="${S}" econf ${myconf}
+}
+
+multilib_src_compile() {
+	emake
+
+	if use unicode; then
+		pushd "${BUILD_DIR}"w >/dev/null
+		emake -C lib
+		popd >/dev/null
+	fi
+}
+
+multilib_src_install() {
+	emake install DESTDIR="${D}"
+
+	if use unicode; then
+		pushd "${BUILD_DIR}"w >/dev/null
+		emake -C lib install DESTDIR="${D}"
+		popd >/dev/null
+
+		pushd "${ED}"/usr/$(get_libdir)/pkgconfig >/dev/null
+		cp expat.pc expatw.pc
+		sed -i -e '/^Libs/s:-lexpat:&w:' expatw.pc || die
+		popd >/dev/null
+	fi
+}
+
+multilib_src_install_all() {
+	einstalldocs
+
+	doman doc/xmlwf.1
+
+	# Note: Use of HTML_DOCS would add unwanted "doc" subfolder
+	docinto html
+	dodoc doc/*.{css,html}
+
+	if use examples; then
+		docinto examples
+		dodoc examples/*.c
+		docompress -x usr/share/doc/${PF}/examples
+	fi
+
+	find "${D}" -name '*.la' -type f -delete || die
+}