Output the storage layout of a contract via storageLayout artifact

test/cmdlineTests/storage_layout_smoke/input.json

@@ -0,0 +1,16 @@
+{
+	"language": "Solidity",
+	"sources": {
+		"fileA": {
+			"content": "contract A { }"
+		}
+	},
+	"settings": {
+		"outputSelection": {
+			"fileA": {
+				"A": [ "storageLayout" ],
+				"": [ "storageLayout" ]
+			}
+		}
+	}
+}

test/cmdlineTests/storage_layout_smoke/output.json

@@ -0,0 +1,4 @@
+{"contracts":{"fileA":{"A":{"storageLayout":{"storage":[],"types":null}}}},"errors":[{"component":"general","formattedMessage":"fileA:1:1: Warning: Source file does not specify required compiler version!
+contract A { }
+^------------^
+","message":"Source file does not specify required compiler version!","severity":"warning","sourceLocation":{"end":14,"file":"fileA","start":0},"type":"Warning"}],"sources":{"fileA":{"id":0}}}