Fix test errors for PYPY.

It looks like PYPY implementation has some issues with strings (or maybe
it's a subprocess bug?). Anyway, this is the full output:

PYTHONWARNINGS=all PSUTIL_TESTING=1 PSUTIL_DEBUG=1 pypy3 -c "import psutil.tests.runner as r; r.run(last_failed=True)"
psutil.tests.test_unicode.TestFSAPIsWithInvalidPath.test_proc_cmdline ... /home/giampaolo/svn/psutil/@psutil-test-30050f��: error while loading shared libraries: libpypy3-c.so: cannot open shared object file: No such file or directory
FAIL
psutil.tests.test_unicode.TestFSAPIsWithInvalidPath.test_proc_exe ... /home/giampaolo/svn/psutil/@psutil-test-30050f��: error while loading shared libraries: libpypy3-c.so: cannot open shared object file: No such file or directory
FAIL
psutil.tests.test_unicode.TestFSAPIsWithInvalidPath.test_proc_name ... /home/giampaolo/svn/psutil/@psutil-test-30050f��: error while loading shared libraries: libpypy3-c.so: cannot open shared object file: No such file or directory
FAIL
psutil.tests.test_process.TestProcess.test_long_cmdline ... /home/giampaolo/svn/psutil/@psutil-test-30050: error while loading shared libraries: libpypy3-c.so: cannot open shared object file: No such file or directory
FAIL
psutil.tests.test_process.TestProcess.test_long_name ... /home/giampaolo/svn/psutil/@psutil-test-3005001234567890123456789: error while loading shared libraries: libpypy3-c.so: cannot open shared object file: No such file or directory
FAIL
psutil.tests.test_process.TestProcess.test_prog_w_funky_name ... /home/giampaolo/svn/psutil/@psutil-test-30050foo bar ): error while loading shared libraries: libpypy3-c.so: cannot open shared object file: No such file or directory
FAIL

======================================================================
FAIL: psutil.tests.test_unicode.TestFSAPIsWithInvalidPath.test_proc_cmdline
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/giampaolo/svn/psutil/psutil/tests/test_unicode.py", line 184, in test_proc_cmdline
    self.assertEqual(cmdline, [self.funky_name])
AssertionError: Lists differ: [] != ['/home/giampaolo/svn/psutil/@psutil-test-30050f\udcc0\udc80']

Second list contains 1 additional elements.
First extra element 0:
'/home/giampaolo/svn/psutil/@psutil-test-30050f\udcc0\udc80'

- []
+ ['/home/giampaolo/svn/psutil/@psutil-test-30050f\udcc0\udc80']

======================================================================
FAIL: psutil.tests.test_unicode.TestFSAPIsWithInvalidPath.test_proc_exe
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/giampaolo/svn/psutil/psutil/tests/test_unicode.py", line 168, in test_proc_exe
    os.path.normcase(self.funky_name))
AssertionError: '' != '/home/giampaolo/svn/psutil/@psutil-test-30050f\udcc0\udc80'
+ /home/giampaolo/svn/psutil/@psutil-test-30050f\udcc0\udc80

======================================================================
FAIL: psutil.tests.test_unicode.TestFSAPIsWithInvalidPath.test_proc_name
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/giampaolo/svn/psutil/psutil/tests/test_unicode.py", line 175, in test_proc_name
    self.assertEqual(name, os.path.basename(self.funky_name))
AssertionError: '@psutil-test-30' != '@psutil-test-30050f\udcc0\udc80'
- @psutil-test-30
+ @psutil-test-30050f\udcc0\udc80
?                ++++++

======================================================================
FAIL: psutil.tests.test_process.TestProcess.test_long_cmdline
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/giampaolo/svn/psutil/psutil/tests/test_process.py", line 736, in test_long_cmdline
    self.assertEqual(p.cmdline(), cmdline)
AssertionError: Lists differ: [] != ['/home/giampaolo/svn/psutil/@psutil-test-[282 chars]789']

Second list contains 21 additional elements.
First extra element 0:
'/home/giampaolo/svn/psutil/@psutil-test-30050'

- []
+ ['/home/giampaolo/svn/psutil/@psutil-test-30050',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789',
+  '0123456789']

======================================================================
FAIL: psutil.tests.test_process.TestProcess.test_long_name
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/giampaolo/svn/psutil/psutil/tests/test_process.py", line 750, in test_long_name
    self.assertEqual(p.name(), os.path.basename(long_name))
AssertionError: '@psutil-test-30' != '@psutil-test-3005001234567890123456789'
- @psutil-test-30
+ @psutil-test-3005001234567890123456789

======================================================================
FAIL: psutil.tests.test_process.TestProcess.test_prog_w_funky_name
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/giampaolo/svn/psutil/psutil/tests/test_process.py", line 780, in test_prog_w_funky_name
    self.assertEqual(p.cmdline(), cmdline)
AssertionError: Lists differ: [] != ['/home/giampaolo/svn/psutil/@psutil-test-[102 chars], '']

Second list contains 7 additional elements.
First extra element 0:
'/home/giampaolo/svn/psutil/@psutil-test-30050foo bar )'

- []
+ ['/home/giampaolo/svn/psutil/@psutil-test-30050foo bar )',
+  '-c',
+  'import time; [time.sleep(0.01) for x in range(3000)];arg1',
+  'arg2',
+  '',
+  'arg3',
+  '']

----------------------------------------------------------------------

3 files changed, 8 insertions, 4 deletions

diff --git a/psutil/_psutil_common.h b/psutil/_psutil_common.h
index e91bf2dd..2fccab81 100644
--- a/psutil/_psutil_common.h
+++ b/psutil/_psutil_common.h
@@ -29,11 +29,11 @@ static const int PSUTIL_CONN_NONE = 128;
 
 // --- _Py_PARSE_PID
 
-// SIZEOF_INT|LONG is missing on Linux + PyPy (only?)
-// SIZEOF_PID_T is missing on Windows + Python2
-// In we can't determine we assume PID is an (int).
+// SIZEOF_INT|LONG is missing on Linux + PyPy (only?).
+// SIZEOF_PID_T is missing on Windows + Python2.
+// In we can't determine pid_t size we assume it's an (int).
 // On major UNIX platforms I've seen pid_t is treated as int.
-// On Windows _getpid() returns an int. We can't be 100% certain though,
+// _getpid() on Windows returns an int. We can't be 100% sure though,
 // (in that case we'd probably get compiler warnings).
 #if !defined(SIZEOF_INT)
     #define SIZEOF_INT 4
diff --git a/psutil/tests/test_process.py b/psutil/tests/test_process.py
index 5728f183..0277a56a 100755
--- a/psutil/tests/test_process.py
+++ b/psutil/tests/test_process.py
@@ -727,6 +727,7 @@ class TestProcess(unittest.TestCase):
             else:
                 raise
 
+    @unittest.skipIf(PYPY, "broken on PYPY")
     def test_long_cmdline(self):
         create_exe(TESTFN)
         self.addCleanup(safe_rmpath, TESTFN)
@@ -741,6 +742,7 @@ class TestProcess(unittest.TestCase):
         pyexe = os.path.basename(os.path.realpath(sys.executable)).lower()
         assert pyexe.startswith(name), (pyexe, name)
 
+    @unittest.skipIf(PYPY, "unreliable on PYPY")
     def test_long_name(self):
         long_name = TESTFN + ("0123456789" * 2)
         create_exe(long_name)
@@ -752,6 +754,7 @@ class TestProcess(unittest.TestCase):
     # XXX
     @unittest.skipIf(SUNOS, "broken on SUNOS")
     @unittest.skipIf(AIX, "broken on AIX")
+    @unittest.skipIf(PYPY, "broken on PYPY")
     def test_prog_w_funky_name(self):
         # Test that name(), exe() and cmdline() correctly handle programs
         # with funky chars such as spaces and ")", see:
diff --git a/psutil/tests/test_unicode.py b/psutil/tests/test_unicode.py
index 91395ebf..eecd7dc4 100644
--- a/psutil/tests/test_unicode.py
+++ b/psutil/tests/test_unicode.py
@@ -298,6 +298,7 @@ class TestFSAPIs(_BaseFSAPIsTests, unittest.TestCase):
 
 @unittest.skipIf(PYPY and TRAVIS, "unreliable on PYPY + TRAVIS")
 @unittest.skipIf(MACOS and TRAVIS, "unreliable on TRAVIS")  # TODO
+@unittest.skipIf(PYPY, "unreliable on PYPY")
 @unittest.skipIf(not subprocess_supports_unicode(INVALID_NAME),
                  "subprocess can't deal with invalid unicode")
 class TestFSAPIsWithInvalidPath(_BaseFSAPIsTests, unittest.TestCase):