Support metadata via IR.

test/libyul/objectCompiler/metadata.yul

@@ -0,0 +1,39 @@
+object "A" {
+  code {
+    pop(datasize("x"))
+    pop(datasize("C"))
+  }
+
+  object "B" {
+    code { pop(dataoffset("other")) }
+    data ".metadata" "M1"
+    data "other" "Hello, World2!"
+  }
+
+  data "C" "ABC"
+  data ".metadata" "M2"
+  data "x" "Hello, World2!"
+}
+// ----
+// Assembly:
+//     /* "source":26:44   */
+//   pop(0x0e)
+//     /* "source":49:67   */
+//   pop(0x03)
+// stop
+// data_211450822d7f8c345093893187e7e1fbebc4ec67af72601920194be14104e336 48656c6c6f2c20576f726c643221
+// data_e1629b9dda060bb30c7908346f6af189c16773fa148d3366701fbaa35d54f3c8 414243
+//
+// sub_0: assembly {
+//         /* "source":99:123   */
+//       pop(data_211450822d7f8c345093893187e7e1fbebc4ec67af72601920194be14104e336)
+//     stop
+//     data_211450822d7f8c345093893187e7e1fbebc4ec67af72601920194be14104e336 48656c6c6f2c20576f726c643221
+//
+//     auxdata: 0x4d31
+// }
+//
+// auxdata: 0x4d32
+// Bytecode: 600e50600350fe4d32
+// Opcodes: PUSH1 0xE POP PUSH1 0x3 POP INVALID 0x4D ORIGIN
+// SourceMappings: 26:18:0:-:0;;49;

test/libyul/yulSyntaxTests/metadata_access.yul

@@ -0,0 +1,32 @@
+object "A" {
+  code {
+    pop(dataoffset(".other"))
+    pop(datasize(".other"))
+    pop(datasize("B..other"))
+    // "B.other" does not exist.
+    pop(datasize("B.other"))
+    // ".metadata" is not accessible by definition
+    pop(dataoffset(".metadata"))
+    pop(datasize(".metadata"))
+    pop(dataoffset("B..metadata"))
+    pop(datasize("B..metadata"))
+  }
+
+  object "B" {
+    code {}
+    data ".metadata" "Hello, World!"
+    data ".other" "Hello, World2!"
+  }
+
+  data ".metadata" "Hello, World!"
+  data ".other" "Hello, World2!"
+}
+// ----
+// TypeError 3517: (41-49): Unknown data object ".other".
+// TypeError 3517: (69-77): Unknown data object ".other".
+// TypeError 3517: (97-107): Unknown data object "B..other".
+// TypeError 3517: (160-169): Unknown data object "B.other".
+// TypeError 3517: (242-253): Unknown data object ".metadata".
+// TypeError 3517: (273-284): Unknown data object ".metadata".
+// TypeError 3517: (306-319): Unknown data object "B..metadata".
+// TypeError 3517: (339-352): Unknown data object "B..metadata".

test/libyul/yulSyntaxTests/metadata_access_2.yul

@@ -0,0 +1,13 @@
+object "A" {
+  code {
+    sstore(dataoffset("0"), dataoffset("1"))
+    sstore(0, datasize(".mightbereservedinthefuture"))
+  }
+
+  data "0"  "UVW"
+  data ".metadata" "ABC"
+  data "1" "XYZ"
+  data ".mightbereservedinthefuture" "TRS"
+}
+// ----
+// TypeError 3517: (90-119): Unknown data object ".mightbereservedinthefuture".

test/libyul/yulSyntaxTests/metadata_access_subobject.yul

@@ -0,0 +1,12 @@
+object "A" {
+	code {
+		sstore(dataoffset(".metadata.x"), 0)
+	}
+
+	object ".metadata" {
+		code {}
+		data "x" "ABC"
+	}
+}
+// ----
+// TypeError 3517: (41-54): Unknown data object ".metadata.x".