py3: have test-revset2.t write test scripts in a more portable way

Fixes the test on Python 3.

Differential Revision: https://phab.mercurial-scm.org/D5763

contrib/python3-whitelist

@@ -630,6 +630,7 b' test-revlog.t'
 test-revset-dirstate-parents.t
 test-revset-legacy-lookup.t
 test-revset-outgoing.t
+test-revset2.t
 test-rollback.t
 test-run-tests.py
 test-run-tests.t

tests/test-revset2.t

@@ -1525,8 +1525,8 b' test author/desc/keyword in problematic '
   $ hg init problematicencoding
   $ cd problematicencoding
 
-  $ "$PYTHON" > setup.sh <<EOF
-  > print(u'''
+  $ "$PYTHON" <<EOF
+  > open('setup.sh', 'wb').write(u'''
   > echo a > text
   > hg add text
   > hg --encoding utf-8 commit -u '\u30A2' -m none
@@ -1541,8 +1541,8 b' test author/desc/keyword in problematic '
   $ sh < setup.sh
 
 test in problematic encoding
-  $ "$PYTHON" > test.sh <<EOF
-  > print(u'''
+  $ "$PYTHON" <<EOF
+  > open('test.sh', 'wb').write(u'''
   > hg --encoding cp932 log --template '{rev}\\n' -r 'author(\u30A2)'
   > echo ====
   > hg --encoding cp932 log --template '{rev}\\n' -r 'author(\u30C2)'