dev-python/pytest: Add PyPy test fix from Debian

Thanks to sbraz for finding the patch.

dev-python/pytest/files/pytest-3.4.2-pypy-syntaxerror-offset.patch

@@ -0,0 +1,27 @@
+https://salsa.debian.org/python-team/modules/pytest/commit/405c05a0827592515de76e23c94de1f7773273e6.patch
+
+From 405c05a0827592515de76e23c94de1f7773273e6 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Ond=C5=99ej=20Nov=C3=BD?= <onovy@debian.org>
+Date: Thu, 10 May 2018 11:42:56 +0200
+Subject: [PATCH] Fix PyPy SyntaxError offset in tests
+
+---
+ testing/code/test_source.py | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/testing/code/test_source.py b/testing/code/test_source.py
+index fcce3fa..22278d8 100644
+--- a/testing/code/test_source.py
++++ b/testing/code/test_source.py
+@@ -117,7 +117,7 @@ def test_source_strip_multiline():
+ def test_syntaxerror_rerepresentation():
+     ex = pytest.raises(SyntaxError, _pytest._code.compile, 'xyz xyz')
+     assert ex.value.lineno == 1
+-    assert ex.value.offset in (4, 7)  # XXX pypy/jython versus cpython?
++    assert ex.value.offset in (4, 5, 7)  # XXX pypy/jython versus cpython?
+     assert ex.value.text.strip(), 'x x'
+ 
+ 
+-- 
+2.18.0
+