Fix tests that are "hard coded" to expect x86_64 output by mocking the platform interface.

Submitted upstream:
https://github.com/pypa/packaging/pull/176

diff --git a/tests/test_tags.py b/tests/test_tags.py
index 1eacf68..0a3f1b4 100644
--- a/tests/test_tags.py
+++ b/tests/test_tags.py
@@ -435,37 +435,43 @@ class TestManylinuxPlatform:
         linux_platform = list(tags._linux_platforms(is_32bit=False))
         assert linux_platform == ["linux_x86_64"]
 
-    def test_linux_platforms_manylinux1(self, monkeypatch):
+    def test_linux_platforms_manylinux1(self, is_x86, monkeypatch):
         monkeypatch.setattr(
             tags, "_is_manylinux_compatible", lambda name, _: name == "manylinux1"
         )
-        if platform.system() != "Linux":
+        if platform.system() != "Linux" or not is_x86:
             monkeypatch.setattr(distutils.util, "get_platform", lambda: "linux_x86_64")
+            monkeypatch.setattr(platform, "machine", lambda: "x86_64")
         platforms = list(tags._linux_platforms(is_32bit=False))
-        assert platforms == ["manylinux1_x86_64", "linux_x86_64"]
+        arch = platform.machine()
+        assert platforms == ["manylinux1_" + arch, "linux_" + arch]
 
-    def test_linux_platforms_manylinux2010(self, monkeypatch):
+    def test_linux_platforms_manylinux2010(self, is_x86, monkeypatch):
         monkeypatch.setattr(
             tags, "_is_manylinux_compatible", lambda name, _: name == "manylinux2010"
         )
-        if platform.system() != "Linux":
+        if platform.system() != "Linux" or not is_x86:
             monkeypatch.setattr(distutils.util, "get_platform", lambda: "linux_x86_64")
+            monkeypatch.setattr(platform, "machine", lambda: "x86_64")
         platforms = list(tags._linux_platforms(is_32bit=False))
-        expected = ["manylinux2010_x86_64", "manylinux1_x86_64", "linux_x86_64"]
+        arch = platform.machine()
+        expected = ["manylinux2010_" + arch, "manylinux1_" + arch, "linux_" + arch]
         assert platforms == expected
 
-    def test_linux_platforms_manylinux2014(self, monkeypatch):
+    def test_linux_platforms_manylinux2014(self, is_x86, monkeypatch):
         monkeypatch.setattr(
             tags, "_is_manylinux_compatible", lambda name, _: name == "manylinux2014"
         )
-        if platform.system() != "Linux":
+        if platform.system() != "Linux" or not is_x86:
             monkeypatch.setattr(distutils.util, "get_platform", lambda: "linux_x86_64")
+            monkeypatch.setattr(platform, "machine", lambda: "x86_64")
         platforms = list(tags._linux_platforms(is_32bit=False))
+        arch = platform.machine()
         expected = [
-            "manylinux2014_x86_64",
-            "manylinux2010_x86_64",
-            "manylinux1_x86_64",
-            "linux_x86_64",
+            "manylinux2014_" + arch,
+            "manylinux2010_" + arch,
+            "manylinux1_" + arch,
+            "linux_" + arch,
         ]
         assert platforms == expected
 
 variables.
(SCM_LOG_COMPILER, AM_SCM_LOG_FLAGS): Delete variables.
(AM_TESTS_ENVIRONMENT): Set GUILE_AUTO_COMPILE to 0.
* test-env.in: Silence guix-daemon.
* doc/guix.texi (Running the Test Suite): Describe how to display the
detailed results.  Bug reports require only 'test-suite.log' file.
* tests/base32.scm, tests/build-utils.scm, tests/builders.scm,
tests/challenge.scm, tests/cpan.scm, tests/cpio.scm, tests/cran.scm,
tests/cve.scm, tests/derivations.scm, tests/elpa.scm,
tests/file-systems.scm, tests/gem.scm, tests/gexp.scm,
tests/gnu-maintenance.scm, tests/grafts.scm, tests/graph.scm,
tests/gremlin.scm, tests/hackage.scm, tests/hash.scm,
tests/import-utils.scm, tests/lint.scm, tests/monads.scm, tests/nar.scm,
tests/packages.scm, tests/pk-crypto.scm, tests/pki.scm,
tests/profiles.scm, tests/publish.scm, tests/pypi.scm,
tests/records.scm, tests/scripts-build.scm, tests/scripts.scm,
tests/services.scm, tests/sets.scm, tests/size.scm, tests/snix.scm,
tests/store.scm, tests/substitute.scm, tests/syscalls.scm,
tests/system.scm, tests/ui.scm, tests/union.scm, tests/upstream.scm,
tests/utils.scm: Don't exit at the end of test groups.
* tests/containers.scm: Likewise.  Use 'test-skip' instead of exiting
with error code 77.
</span></span></td><td>Mathieu Lirzin</td></tr>
<tr><td><span title='2015-10-06 23:51:04 +0200'>2015-10-06</span></td><td><a href='/guix/commit/tests/snix.scm?id=f073e52382d2ddcc638de73533bbf798f600d78a'>utils: Remove Nixpkgs helpers.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/config.scm.in (%nixpkgs): Remove.
* guix/utils.scm (%nixpkgs-directory, nixpkgs-derivation,
  nixpkgs-derivation*): Remove.
* test-env.in: Export 'NIXPKGS'.
* tests/derivations.scm (%coreutils): Remove use of
  'nixpkgs-derivation'.
* tests/snix.scm (%nixpkgs-directory): New variable.
  Adjust users accordingly.
</span></span></td><td>Ludovic Courtès</td></tr>