New folder localStorageVariable for new testcases; added two new tests

test/libsolidity/syntaxTests/controlFlow/localStorageVariables/ternary_assignment_err.sol

@@ -0,0 +1,11 @@
+contract C {
+    uint256[] s;
+    function f() public {
+        bool d;
+        uint256[] storage x;
+        uint256[] storage y = d ? (x = s) : x;
+        y;
+    }
+}
+// ----
+// TypeError: (145-146): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/controlFlow/localStorageVariables/ternary_assignment_fine.sol

@@ -0,0 +1,9 @@
+contract C {
+    uint256[] s;
+    function f() public view {
+        uint256[] storage x;
+        uint256[] storage y = (x = s)[0] > 0 ? x : x;
+        y;
+    }
+}
+// ---