Add tests.

test/libyul/objectCompiler/data.yul

@@ -0,0 +1,11 @@
+object "a" {
+  code {}
+  // Unreferenced data is not added to the assembled bytecode.
+  data "str" "Hello, World!"
+}
+// ----
+// Assembly:
+// stop
+// data_acaf3289d7b601cbd114fb36c4d29c85bbfd5e133f14cb355c3fd8d99367964f 48656c6c6f2c20576f726c6421
+// Bytecode: fe
+// Opcodes: INVALID

test/libyul/objectCompiler/namedObject.yul

@@ -0,0 +1,6 @@
+object "a" {
+  code {}
+}
+// ----
+// Assembly:
+// -- empty bytecode --

test/libyul/objectCompiler/namedObjectCode.yul

@@ -0,0 +1,13 @@
+object "a" {
+  code { sstore(0, 1) }
+}
+// ----
+// Assembly:
+//     /* "source":32:33   */
+//   0x01
+//     /* "source":29:30   */
+//   0x00
+//     /* "source":22:34   */
+//   sstore
+// Bytecode: 6001600055
+// Opcodes: PUSH1 0x1 PUSH1 0x0 SSTORE

test/libyul/objectCompiler/nested_optimizer.yul

@@ -0,0 +1,49 @@
+// optimize
+object "a" {
+  code {
+    let x := calldataload(0)
+    let y := calldataload(0)
+    let z := sub(y, x)
+    sstore(add(x, 0), z)
+  }
+  object "sub" {
+    code {
+      let x := calldataload(0)
+      let y := calldataload(0)
+      let z := sub(y, x)
+      sstore(add(x, 0), z)
+    }
+  }
+}
+// ----
+// Assembly:
+//     /* "source":60:61   */
+//   0x00
+//     /* "source":137:138   */
+//   dup1
+//     /* "source":60:61   */
+//   dup2
+//     /* "source":47:62   */
+//   calldataload
+//     /* "source":119:139   */
+//   sstore
+//     /* "source":32:143   */
+//   pop
+// stop
+//
+// sub_0: assembly {
+//         /* "source":200:201   */
+//       0x00
+//         /* "source":283:284   */
+//       dup1
+//         /* "source":200:201   */
+//       dup2
+//         /* "source":187:202   */
+//       calldataload
+//         /* "source":265:285   */
+//       sstore
+//         /* "source":170:291   */
+//       pop
+// }
+// Bytecode: 60008081355550fe
+// Opcodes: PUSH1 0x0 DUP1 DUP2 CALLDATALOAD SSTORE POP INVALID

test/libyul/objectCompiler/simple.yul

@@ -0,0 +1,13 @@
+{
+  sstore(0, 1)
+}
+// ----
+// Assembly:
+//     /* "source":14:15   */
+//   0x01
+//     /* "source":11:12   */
+//   0x00
+//     /* "source":4:16   */
+//   sstore
+// Bytecode: 6001600055
+// Opcodes: PUSH1 0x1 PUSH1 0x0 SSTORE

test/libyul/objectCompiler/simple_optimizer.yul

@@ -0,0 +1,23 @@
+// optimize
+{
+  let x := calldataload(0)
+  let y := calldataload(0)
+  let z := sub(y, x)
+  sstore(add(x, 0), z)
+}
+// ----
+// Assembly:
+//     /* "source":38:39   */
+//   0x00
+//     /* "source":109:110   */
+//   dup1
+//     /* "source":38:39   */
+//   dup2
+//     /* "source":25:40   */
+//   calldataload
+//     /* "source":91:111   */
+//   sstore
+//     /* "source":12:113   */
+//   pop
+// Bytecode: 60008081355550
+// Opcodes: PUSH1 0x0 DUP1 DUP2 CALLDATALOAD SSTORE POP

test/libyul/objectCompiler/smoke.yul

@@ -0,0 +1,5 @@
+{
+}
+// ----
+// Assembly:
+// -- empty bytecode --

test/libyul/objectCompiler/subObject.yul

@@ -0,0 +1,21 @@
+object "a" {
+  code {}
+  // Unreferenced data is not added to the assembled bytecode.
+  data "str" "Hello, World!"
+  object "sub" { code { sstore(0, 1) } }
+}
+// ----
+// Assembly:
+// stop
+// data_acaf3289d7b601cbd114fb36c4d29c85bbfd5e133f14cb355c3fd8d99367964f 48656c6c6f2c20576f726c6421
+//
+// sub_0: assembly {
+//         /* "source":149:150   */
+//       0x01
+//         /* "source":146:147   */
+//       0x00
+//         /* "source":139:151   */
+//       sstore
+// }
+// Bytecode: fe
+// Opcodes: INVALID

test/libyul/objectCompiler/subSubObject.yul

@@ -0,0 +1,39 @@
+object "a" {
+  code {}
+  // Unreferenced data is not added to the assembled bytecode.
+  data "str" "Hello, World!"
+  object "sub" {
+    code { sstore(0, 1) }
+    object "subsub" {
+      code { sstore(2, 3) }
+      data "str" hex"123456"
+    }
+  }
+}
+// ----
+// Assembly:
+// stop
+// data_acaf3289d7b601cbd114fb36c4d29c85bbfd5e133f14cb355c3fd8d99367964f 48656c6c6f2c20576f726c6421
+//
+// sub_0: assembly {
+//         /* "source":153:154   */
+//       0x01
+//         /* "source":150:151   */
+//       0x00
+//         /* "source":143:155   */
+//       sstore
+//     stop
+//
+//     sub_0: assembly {
+//             /* "source":203:204   */
+//           0x03
+//             /* "source":200:201   */
+//           0x02
+//             /* "source":193:205   */
+//           sstore
+//         stop
+//         data_6adf031833174bbe4c85eafe59ddb54e6584648c2c962c6f94791ab49caa0ad4 123456
+//     }
+// }
+// Bytecode: fe
+// Opcodes: INVALID