Code generation for errors.

test/libsolidity/semanticTests/errors/named_error_args.sol

@@ -0,0 +1,10 @@
+error E(uint a, uint b);
+contract C {
+    function f() public pure {
+        revert(E({b: 7, a: 2}));
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// f() -> FAILURE, hex"85208890", hex"0000000000000000000000000000000000000000000000000000000000000002", hex"0000000000000000000000000000000000000000000000000000000000000007"

test/libsolidity/semanticTests/errors/named_require.sol

@@ -0,0 +1,11 @@
+error E(uint a, uint b);
+contract C {
+    function f(bool c) public pure {
+        require(c, E({b: 7, a: 2}));
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// f(bool): true ->
+// f(bool): false -> FAILURE, hex"85208890", hex"0000000000000000000000000000000000000000000000000000000000000002", hex"0000000000000000000000000000000000000000000000000000000000000007"

test/libsolidity/semanticTests/errors/require_conversion.sol

@@ -0,0 +1,13 @@
+error E(string a, uint[] b);
+contract C {
+    uint[] x;
+    function f(bool c) public {
+        x.push(7);
+        require(c, E("abc", x));
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// f(bool): false -> FAILURE, hex"59e4d4df", 0x40, 0x80, 3, "abc", 1, 7
+// f(bool): true ->

test/libsolidity/semanticTests/errors/require_side_effects.sol

@@ -0,0 +1,19 @@
+error E(uint a, uint b);
+contract C {
+    uint public x;
+    function f(bool c) public {
+        require(c, E(g(), 7));
+    }
+    function g() public returns (uint) {
+        x++;
+        return 2;
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// x() -> 0
+// f(bool): true ->
+// x() -> 1
+// f(bool): false -> FAILURE, hex"85208890", hex"0000000000000000000000000000000000000000000000000000000000000002", hex"0000000000000000000000000000000000000000000000000000000000000007"
+// x() -> 1

test/libsolidity/semanticTests/errors/revert_conversion.sol

@@ -0,0 +1,12 @@
+error E(string a, uint[] b);
+contract C {
+    uint[] x;
+    function f() public {
+        x.push(7);
+        revert(E("abc", x));
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// f() -> FAILURE, hex"59e4d4df", 0x40, 0x80, 3, "abc", 1, 7

test/libsolidity/semanticTests/errors/simple.sol

@@ -0,0 +1,10 @@
+error E(uint a, uint b);
+contract C {
+    function f() public pure {
+        revert(E(2, 7));
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// f() -> FAILURE, hex"85208890", 2, 7

test/libsolidity/semanticTests/errors/simple_require.sol

@@ -0,0 +1,11 @@
+error E(uint a, uint b);
+contract C {
+    function f(bool c) public pure {
+        require(c, E(2, 7));
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// f(bool): true ->
+// f(bool): false -> FAILURE, hex"85208890", hex"0000000000000000000000000000000000000000000000000000000000000002", hex"0000000000000000000000000000000000000000000000000000000000000007"