tests/basics: Automatically skip tests that use str/bytes modulo-format.

tests/basics/bytes_format_modulo.py

@@ -1,4 +1,11 @@
 # This test requires CPython3.5
+
+try:
+    b'' % ()
+except TypeError:
+    print("SKIP")
+    raise SystemExit
+
 print(b"%%" % ())
 print(b"=%d=" % 1)
 print(b"=%d=%d=" % (1, 2))

tests/basics/string_format_modulo.py

@@ -1,3 +1,9 @@
+try:
+    '' % ()
+except TypeError:
+    print("SKIP")
+    raise SystemExit
+
 print("%%" % ())
 print("=%s=" % 1)
 print("=%s=%s=" % (1, 2))

tests/basics/string_format_modulo_int.py

@@ -1,5 +1,11 @@
 # test string modulo formatting with int values
 
+try:
+    '' % ()
+except TypeError:
+    print("SKIP")
+    raise SystemExit
+
 # basic cases
 print("%d" % 10)
 print("%+d" % 10)