Clear all mapping knowledge after array variable assignment

test/libsolidity/smtCheckerTests/types/mapping_aliasing_1.sol

@@ -7,9 +7,12 @@ contract C
 
 	function f() public {
 		require(a[1] == b[1]);
+		a[1] = 2;
 		mapping (uint => uint) storage c = a;
-		c[1] = 2;
+		assert(c[1] == 2);
 		// False negative! Needs aliasing.
 		assert(a[1] == b[1]);
 	}
 }
+// ----
+// Warning: (261-281): Assertion violation happens here