Fix some tests

cpython/patches/dont-test-undecodable-filenames.patch

@@ -0,0 +1,13 @@
+diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py
+index ddcd2cc387..f422f2feb6 100644
+--- a/Lib/test/support/__init__.py
++++ b/Lib/test/support/__init__.py
+@@ -880,6 +880,8 @@ if os.name == 'nt':
+                   'Unicode filename tests may not be effective'
+                   % (TESTFN_UNENCODABLE, TESTFN_ENCODING))
+             TESTFN_UNENCODABLE = None
++elif sys.platform == 'emscripten':
++    pass
+ # Mac OS X denies unencodable filenames (invalid utf-8)
+ elif sys.platform != 'darwin':
+     try:

test/python_tests.txt

@@ -295,7 +295,7 @@ test_lzma
 test_macpath  platform-specific
 test_macurl2path
 test_mailbox  crash
-test_mailcap
+test_mailcap  nonsense
 test_marshal
 test_math floating-point
 test_memoryio