-arch <arch> detection in _osx_support generates false positives

[isuruf]

BPO	47154
Nosy	@ronaldoussoren, @ned-deily, @isuruf
PRs	bpo-47154: make the macos detection of archs more robust #32178

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = 'https://github.com/ned-deily'
closed_at = None
created_at = <Date 2022-03-29.17:35:29.198>
labels = ['OS-mac', 'build', '3.9', '3.10', '3.11']
title = '-arch <arch> detection in _osx_support generates false positives'
updated_at = <Date 2022-03-29.21:13:55.846>
user = 'https://github.com/isuruf'

bugs.python.org fields:

activity = <Date 2022-03-29.21:13:55.846>
actor = 'dom1310df'
assignee = 'ned.deily'
closed = False
closed_date = None
closer = None
components = ['Build', 'macOS']
creation = <Date 2022-03-29.17:35:29.198>
creator = 'isuruf'
dependencies = []
files = []
hgrepos = []
issue_num = 47154
keywords = ['patch']
message_count = 2.0
messages = ['416278', '416280']
nosy_count = 4.0
nosy_names = ['ronaldoussoren', 'ned.deily', 'isuruf', 'dom1310df']
pr_nums = ['32178']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = None
url = 'https://bugs.python.org/issue47154'
versions = ['Python 3.9', 'Python 3.10', 'Python 3.11']

[isuruf]

If cflags contains something like, -I/Users/isuru/handy-archives-env/include, then the code assumes that there is a -arch flag in it and errors with

ValueError: Don't know machine value for archs=()

[ned-deily]

Duplicate of bpo-46691 but since you've provide a PR, we'll follow up with this one, thanks.