[Sol2Yul] Implements codegen part for try/catch statements.

test/libsolidity/semanticTests/tryCatch/lowLevel.sol

@@ -12,6 +12,7 @@ contract C {
     }
 }
 // ====
+// compileViaYul: also
 // EVMVersion: >=byzantium
 // ----
 // f(bool): true -> 1, 2, 96, 0

test/libsolidity/semanticTests/tryCatch/nested.sol

@@ -26,6 +26,7 @@ contract C {
 }
 // ====
 // EVMVersion: >=byzantium
+// compileViaYul: also
 // ----
 // f(bool,bool): true, true -> 1, 2, 96, 7, "success"
 // f(bool,bool): true, false -> 12, 0, 96, 7, "failure"

test/libsolidity/semanticTests/tryCatch/return_function.sol

@@ -13,5 +13,7 @@ contract C {
     }
     function fun() public pure {}
 }
+// ====
+// compileViaYul: also
 // ----
 // f() -> 0x1, 0xfdd67305928fcac8d213d1e47bfa6165cd0b87b946644cd0000000000000000, 9

test/libsolidity/semanticTests/tryCatch/simple.sol

@@ -1,10 +1,10 @@
 contract C {
-    function g(bool b) public pure returns (uint, uint) {
+    function g(bool b) public pure returns (uint x, uint y) {
         require(b);
         return (1, 2);
     }
-    function f(bool b) public returns (uint x, uint y) {
-        try this.g(b) returns (uint a, uint b) {
+    function f(bool flag) public view returns (uint x, uint y) {
+        try this.g(flag) returns (uint a, uint b) {
             (x, y) = (a, b);
         } catch {
             (x, y) = (9, 10);
@@ -13,6 +13,7 @@ contract C {
 }
 // ====
 // EVMVersion: >=byzantium
+// compileViaYul: also
 // ----
 // f(bool): true -> 1, 2
 // f(bool): false -> 9, 10

test/libsolidity/semanticTests/tryCatch/simple_notuple.sol

@@ -0,0 +1,19 @@
+contract C {
+    function g(bool b) public pure returns (uint x) {
+        require(b);
+        return 13;
+    }
+    function f(bool flag) public view returns (uint x) {
+        try this.g(flag) returns (uint a) {
+            x = a;
+        } catch {
+            x = 9;
+        }
+    }
+}
+// ====
+// EVMVersion: >=byzantium
+// compileViaYul: also
+// ----
+// f(bool): true -> 13
+// f(bool): false -> 9

test/libsolidity/semanticTests/tryCatch/structured.sol

@@ -14,6 +14,7 @@ contract C {
 }
 // ====
 // EVMVersion: >=byzantium
+// compileViaYul: also
 // ----
 // f(bool): true -> 1, 2, 0x60, 7, "success"
 // f(bool): false -> 0, 0, 0x60, 7, "message"

test/libsolidity/semanticTests/tryCatch/structuredAndLowLevel.sol

@@ -18,6 +18,7 @@ contract C {
 }
 // ====
 // EVMVersion: >=byzantium
+// compileViaYul: also
 // ----
 // f(bool): true -> 1, 2, 96, 7, "success"
 // f(bool): false -> 99, 0, 96, 82, "message longer than 32 bytes 32 ", "bytes 32 bytes 32 bytes 32 bytes", " 32 bytes 32 bytes"

test/libsolidity/semanticTests/tryCatch/super_trivial.sol

@@ -0,0 +1,18 @@
+contract C {
+    function g(bool x) external pure {
+        require(x);
+    }
+    function f(bool x) public returns (uint) {
+        try this.g(x) {
+            return 1;
+        } catch {
+            return 2;
+        }
+    }
+}
+// ====
+// EVMVersion: >=byzantium
+// compileViaYul: also
+// ----
+// f(bool): true -> 1
+// f(bool): false -> 2