Update run-strings.test

Author: BobTheBuidler

mypyc/test-data/run-strings.test

@@ -822,6 +822,11 @@ def test_count() -> None:
     assert string.count("a") == 1
     assert string.count("b") == 3
     assert string.count("c") == 2
+def test_count_start() -> None:
+    string = "abcbcb"
+    assert string.count("a", 2) == 0
+    assert string.count("b", 2) == 2
+    assert string.count("c", 2) == 2
 def test_count_start_end() -> None:
     string = "abcbcb"
     assert string.count("a", 0, 4) == 1