tests: Add test of invalid unicode strings.

.. from non UTF-8 inputs. In this case, MicroPython raises
UnicodeError while CPython uses SyntaxError. By catching either
exception, the test does not require an .exp file.

Signed-off-by: Jeff Epler <jepler@gmail.com>

tests/unicode/unicode_parser.py

@@ -0,0 +1,23 @@
+# test invalid UTF-8 string via eval
+# Passing byte strings to exec/eval is a micropython extension
+try:
+    eval(b"'ab\xa1'")
+except SyntaxError:
+    print("Exception")
+try:
+    eval(b"'ab\xf8'")
+except SyntaxError:
+    print("Exception")
+try:
+    eval(bytearray(b"'ab\xc0a'"))
+except SyntaxError:
+    print("Exception")
+try:
+    eval(b"'\xf0\xe0\xed\xe8'")
+except SyntaxError:
+    print("Exception")
+
+try:
+    exec(b"b\xff = 1")
+except SyntaxError:
+    print("Exception")