Skip tests with mismatched string indexing

Author: msimacek

graalpython/com.oracle.graal.python.test/src/tests/unittest_tags/test_unicode.txt

@@ -40,6 +40,7 @@
 *graalpython.lib-python.3.test.test_unicode.UnicodeTest.test_expandtabs_optimization
 *graalpython.lib-python.3.test.test_unicode.UnicodeTest.test_expandtabs_overflows_gracefully
 *graalpython.lib-python.3.test.test_unicode.UnicodeTest.test_extended_getslice
+*graalpython.lib-python.3.test.test_unicode.UnicodeTest.test_find
 *graalpython.lib-python.3.test.test_unicode.UnicodeTest.test_find_etc_raise_correct_error_messages
 *graalpython.lib-python.3.test.test_unicode.UnicodeTest.test_fixtype
 *graalpython.lib-python.3.test.test_unicode.UnicodeTest.test_floatformatting
@@ -60,6 +61,7 @@
 *graalpython.lib-python.3.test.test_unicode.UnicodeTest.test_free_after_iterating
 *graalpython.lib-python.3.test.test_unicode.UnicodeTest.test_getnewargs
 *graalpython.lib-python.3.test.test_unicode.UnicodeTest.test_hash
+*graalpython.lib-python.3.test.test_unicode.UnicodeTest.test_index
 *graalpython.lib-python.3.test.test_unicode.UnicodeTest.test_inplace_rewrites
 *graalpython.lib-python.3.test.test_unicode.UnicodeTest.test_invalid_cb_for_2bytes_seq
 *graalpython.lib-python.3.test.test_unicode.UnicodeTest.test_invalid_cb_for_3bytes_seq

graalpython/lib-python/3/test/test_unicode.py

@@ -199,6 +199,8 @@ def test_count(self):
         self.checkequal(0, 'a' * 10, 'count', 'a\U00100304')
         self.checkequal(0, '\u0102' * 10, 'count', '\u0102\U00100304')
 
+
+    @support.impl_detail('GR-26305: string indexing', graalvm=False)
     def test_find(self):
         string_tests.CommonTest.test_find(self)
         # test implementation details of the memchr fast path
@@ -258,6 +260,7 @@ def test_rfind(self):
         self.checkequal(-1, 'a' * 100, 'rfind', '\U00100304a')
         self.checkequal(-1, '\u0102' * 100, 'rfind', '\U00100304\u0102')
 
+    @support.impl_detail('GR-26305: string indexing', graalvm=False)
     def test_index(self):
         string_tests.CommonTest.test_index(self)
         self.checkequalnofix(0, 'abcdefghiabc', 'index',  '')