dev-lang/python-oem: use python from python-build-standalone project

Our python-oem is minimal and doesn't support pip or most of the standard
library. This is an attempt to see whether using a prebuilt python
distribution works to support Azure extensions.

It was necessary to add a symlink to 'python' executable and lib64 dir to avoid
having to change distro-oem and waagent ebuilds.

dev-lang/python-oem/Manifest

@@ -1,2 +1,5 @@
 DIST Python-3.9.8.tar.xz 19149464 BLAKE2B 739eb22bae8b44cf5be9a24ca6ecacb80eaca65684abf1fef18b7adcac9adede2eff60e8a9ac5db2672511d180d6079c39e2ff2901ab454c0876ae8e1bfe96cc SHA512 5d5b46a242525b2e6a7f9c69c63c6d7cd985e1443a7d9b716107e75f14fef7b5c9c2e5e8a90adbbbf5f7a8b90a483d01e18c1732470e6e54b611b5aba9f99fe1
+DIST Python-3.9.8.tar.xz.asc 833 BLAKE2B ec94293d0d28398b425a0a6cd502f6540b23f6788874160216d0575fe23a4ad8e5636c5d4deae7bc193d00bd18aff12f935a6ea807786a87f041046d6693fd20 SHA512 1329a8e114feb010bb3618472cddd9fdea59fc38e9583002eb457e1c0cf1716bd7c0d51887e91b9eef09c3977879aa4be9909e5997be7dfdcca08ca04794bfaf
+DIST cpython-3.9.11+20220318-aarch64-unknown-linux-gnu-install_only.tar.gz 86614999 BLAKE2B a76cfaff74f52c30afeee4082fbf17f2beb9660e2240bd75a0bb97f7e76bb7de88664d87cfdfbec09dcf1638929c42bb0a1750a0ebd963c5a86b0efa6ff3b66d SHA512 0eb13bbe1c52a129c5a45824a5dd5be53a607257bf5e4cfbec3998e6ba113d4d0fd35e086117b3be3632109052111cab437dc80ad085b3122e1d13afa095a08e
+DIST cpython-3.9.11+20220318-x86_64_v2-unknown-linux-gnu-install_only.tar.gz 51943652 BLAKE2B ae7ad6cb41b3d91e61989c20f120729319c42542a65b0b1c2e1a499a5f04adb1c0892c5d9e5e61ba196acde40c3a11cb83e379141a411bb47e60ccc7f3e28af0 SHA512 325504f94f5f51930a15799777e50ffb0d42eb1f074414d7281e681d04ee621a5d82978255b00fa3054240908b2ccae00c6f853261ef3c87a54fdd95cb18cad2
 DIST python-gentoo-patches-3.9.8.tar.xz 13192 BLAKE2B 995bead7e87b1d2eb9984012065c0f752d51e5a78dd9019270e071f83660cdab71c39e5be0104919f5af9089dede71d9c918a521f76e67c6ef1aeab5ffb58991 SHA512 80dfa3766bb5546924a5fccf4f469ce409cb8a4b0873c3d2fb737b3eb27b7c2b29337e0179624bbe077273b8e475f7921d6479ca7eb8e31ba423d0cea2f3d1cf

dev-lang/python-oem/python-oem-3.9.11.ebuild

@@ -0,0 +1,32 @@
+# Copyright 2022 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+DESCRIPTION="This project produces self-contained, highly-portable Python distributions."
+HOMEPAGE="https://github.com/indygreg/python-build-standalone/"
+SRC_URI="
+	amd64? ( https://github.com/indygreg/python-build-standalone/releases/download/20220318/cpython-3.9.11+20220318-x86_64_v2-unknown-linux-gnu-install_only.tar.gz )
+	arm64? ( https://github.com/indygreg/python-build-standalone/releases/download/20220318/cpython-3.9.11+20220318-aarch64-unknown-linux-gnu-install_only.tar.gz )
+"
+PYVER=$(ver_cut 1-2)
+
+# TODO: many more licenses are needed
+LICENSE="PSF-2"
+SLOT="${PYVER}"
+KEYWORDS="amd64 arm64"
+
+# TODO: minimal host dependencies, may be we can express those?
+DEPEND=""
+RDEPEND="${DEPEND}"
+BDEPEND=""
+
+S="${WORKDIR}"
+
+src_install() {
+	dodir /usr/share/oem
+	cp -a ${S}/python ${ED}/usr/share/oem
+	find ${ED} -name 'lib*.a' -delete
+	dosym python3 /usr/share/oem/python/bin/python
+	dosym lib /usr/share/oem/python/lib64
+}