add example cases for incorrect E275 from reverted patch

Author: asottile

testsuite/E27.py

@@ -42,3 +42,5 @@
     from importable.module import(e, f)
 except ImportError:
     pass
+#: Okay
+matched = {"true": True, "false": False}

testsuite/python3.py

@@ -9,6 +9,8 @@ def foo(x: int) -> int:
 
 # Annotated variables #575
 CONST: int = 42
+match: int = 42
+case: int = 42
 
 
 class Class: