Scanner: Generate error on inbalanced RLO/LRO/PDF override markers.

test/libsolidity/syntaxTests/comments/multiline_unicode_direction_override_1.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure
+    {
+        // PDF
+        /*underflow ‬*/
+    }
+}
+// ----
+// ParserError 8936: (71-83): Unicode direction override underflow in comment or string literal.

test/libsolidity/syntaxTests/comments/multiline_unicode_direction_override_2.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure
+    {
+        // PDF PDF
+        /*underflow ‬‬*/
+    }
+}
+// ----
+// ParserError 8936: (75-87): Unicode direction override underflow in comment or string literal.

test/libsolidity/syntaxTests/comments/multiline_unicode_direction_override_3.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure
+    {
+        // RLO
+        /*overflow ‮*/
+    }
+}
+// ----
+// ParserError 8936: (71-86): Mismatching directional override markers in comment or string literal.

test/libsolidity/syntaxTests/comments/multiline_unicode_direction_override_4.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure
+    {
+        // RLO RLO
+        /*overflow ‮‮*/
+    }
+}
+// ----
+// ParserError 8936: (75-93): Mismatching directional override markers in comment or string literal.

test/libsolidity/syntaxTests/comments/multiline_unicode_direction_override_5.sol

@@ -0,0 +1,14 @@
+contract C {
+    function f() public pure
+    {
+        // RLO PDF
+        /*ok ‮‬*/
+
+        // RLO RLO PDF PDF
+        /*ok ‮‮‬‬*/
+
+        // RLO RLO RLO PDF PDF PDF
+        /*ok ‮‮‮‬‬‬*/
+    }
+}
+// ----

test/libsolidity/syntaxTests/comments/multiline_unicode_direction_override_6.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure
+    {
+        // PDF RLO
+        /*overflow ‬‮*/
+    }
+}
+// ----
+// ParserError 8936: (75-86): Unicode direction override underflow in comment or string literal.

test/libsolidity/syntaxTests/comments/multiline_unicode_direction_override_7.sol

@@ -0,0 +1,7 @@
+contract C {
+    function f() public pure {
+        /* LRO‭ LRE‪ RLE ‫  PDF‬ RLO‮ PDF ‬ PDF‬
+    }
+}
+// ----
+// ParserError 8936: (52-115): Expected multi-line comment-terminator.

test/libsolidity/syntaxTests/comments/singleline_unicode_direction_override_1.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure
+    {
+        // PDF
+        // underflow ‬
+    }
+}
+// ----
+// ParserError 8936: (71-84): Unicode direction override underflow in comment or string literal.

test/libsolidity/syntaxTests/comments/singleline_unicode_direction_override_2.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure
+    {
+        // PDF PDF
+        // underflow ‬‬
+    }
+}
+// ----
+// ParserError 8936: (75-88): Unicode direction override underflow in comment or string literal.

test/libsolidity/syntaxTests/comments/singleline_unicode_direction_override_3.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure
+    {
+        // RLO
+        // overflow ‮
+    }
+}
+// ----
+// ParserError 8936: (71-86): Mismatching directional override markers in comment or string literal.

test/libsolidity/syntaxTests/comments/singleline_unicode_direction_override_4.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure
+    {
+        // RLO RLO
+        // overflow ‮‮
+    }
+}
+// ----
+// ParserError 8936: (75-93): Mismatching directional override markers in comment or string literal.

test/libsolidity/syntaxTests/comments/singleline_unicode_direction_override_5.sol

@@ -0,0 +1,14 @@
+contract C {
+    function f() public pure
+    {
+        // RLO PDF
+        // ok ‮‬
+
+        // RLO RLO PDF PDF
+        // ok ‮‮‬‬
+
+        // RLO RLO RLO PDF PDF PDF
+        // ok ‮‮‮‬‬‬
+    }
+}
+// ----

test/libsolidity/syntaxTests/comments/singleline_unicode_direction_override_6.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure
+    {
+        // PDF RLO
+        // underflow ‬‮
+    }
+}
+// ----
+// ParserError 8936: (75-88): Unicode direction override underflow in comment or string literal.

test/libsolidity/syntaxTests/comments/unicode_direction_in_source_1.sol

@@ -0,0 +1,8 @@
+contract C {
+    function f(bool b) public pure
+    {
+        if ‬(b) { return; }
+    }
+}
+// ----
+// ParserError 2314: (65-66): Expected '(' but got 'ILLEGAL'

test/libsolidity/syntaxTests/comments/unicode_direction_in_source_2.sol

@@ -0,0 +1,8 @@
+contract C {
+    function f(bool b) public pure
+    {
+        uint a = 10; ‬
+    }
+}
+// ----
+// ParserError 8936: (75-76): Invalid token.

test/libsolidity/syntaxTests/comments/unicode_direction_override_1.sol

@@ -0,0 +1,10 @@
+contract TimelockUpgrade {
+    function confirmUpgrade() external {
+        uint256 m;
+        uint256 d;
+        (/*year*/,/*month‮*/,d/*yad*/,m/*‬‬hour*/,/*minute*/,/*second*/) = BokkyDateTime.timestampToDateTime(block.timestamp);
+    }
+}
+
+// ----
+// ParserError 8936: (128-139): Mismatching directional override markers in comment or string literal.

test/libsolidity/syntaxTests/literals/unicode_string_direction_override_1.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure
+    {
+        // PDF
+        bytes memory s = unicode"underflow ‬";
+    }
+}
+// ----
+// ParserError 8936: (88-106): Unicode direction override underflow in comment or string literal.

test/libsolidity/syntaxTests/literals/unicode_string_direction_override_2.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure
+    {
+        // PDF PDF
+        bytes memory m = unicode"underflow ‬‬";
+    }
+}
+// ----
+// ParserError 8936: (92-110): Unicode direction override underflow in comment or string literal.

test/libsolidity/syntaxTests/literals/unicode_string_direction_override_3.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure
+    {
+        // RLO
+        bytes memory m = unicode"overflow ‮";
+    }
+}
+// ----
+// ParserError 8936: (88-108): Mismatching directional override markers in comment or string literal.

test/libsolidity/syntaxTests/literals/unicode_string_direction_override_4.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure
+    {
+        // RLO RLO
+        bytes memory m = unicode"overflow ‮‮";
+    }
+}
+// ----
+// ParserError 8936: (92-115): Mismatching directional override markers in comment or string literal.

test/libsolidity/syntaxTests/literals/unicode_string_direction_override_5.sol

@@ -0,0 +1,14 @@
+contract C {
+    function f() public pure
+    {
+        // RLO PDF
+        bytes memory m = unicode" ok ‮‬";
+
+        // RLO RLO PDF PDF
+        m = unicode" ok ‮‮‬‬";
+
+        // RLO RLO RLO PDF PDF PDF
+        m = unicode" ok ‮‮‮‬‬‬";
+    }
+}
+// ----

test/libsolidity/syntaxTests/literals/unicode_string_direction_override_6.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure
+    {
+        // PDF RLO
+        bytes memory m = unicode" underflow ‬‮";
+    }
+}
+// ----
+// ParserError 8936: (92-111): Unicode direction override underflow in comment or string literal.

test/libsolidity/syntaxTests/literals/unicode_string_direction_override_7.sol

@@ -0,0 +1,13 @@
+contract C {
+    function f() public pure
+    {
+        // LRO PDF RLO PDF
+        bytes memory m = unicode"‭ ok ‬‮‬";
+
+        // lre rle pdf pdf
+        m = unicode"lre‪ rle‫ pdf‬ pdf‬";
+        // lre lro pdf pdf
+        m = unicode"lre‪ lro‭ pdf‬ pdf‬";
+    }
+}
+// ----