use compound tasks for selfhost

.vscode/tasks.json

@@ -3,12 +3,8 @@
 	"tasks": [
 		{
 			"type": "npm",
-			"script": "watchd",
-			"label": "Build VS Code",
-			"group": {
-				"kind": "build",
-				"isDefault": true
-			},
+			"script": "watch-clientd",
+			"label": "Build VS Code Core",
 			"isBackground": true,
 			"presentation": {
 				"reveal": "never"
@@ -26,11 +22,48 @@
 					"message": 3
 				},
 				"background": {
-					"beginsPattern": "\\[watch-client\\].*Starting compilation",
-					"endsPattern": "\\[watch-client\\].*Finished compilation"
+					"beginsPattern": "Starting compilation",
+					"endsPattern": "Finished compilation"
 				}
 			}
 		},
+		{
+			"type": "npm",
+			"script": "watch-extensionsd",
+			"label": "Build VS Code Extensions",
+			"isBackground": true,
+			"presentation": {
+				"reveal": "never"
+			},
+			"problemMatcher": {
+				"owner": "typescript",
+				"applyTo": "closedDocuments",
+				"fileLocation": [
+					"absolute"
+				],
+				"pattern": {
+					"regexp": "Error: ([^(]+)\\((\\d+|\\d+,\\d+|\\d+,\\d+,\\d+,\\d+)\\): (.*)$",
+					"file": 1,
+					"location": 2,
+					"message": 3
+				},
+				"background": {
+					"beginsPattern": "Starting compilation",
+					"endsPattern": "Finished compilation"
+				}
+			}
+		},
+		{
+			"label": "Build VS Code",
+			"dependsOn": [
+				"Build VS Code Core",
+				"Build VS Code Extensions"
+			],
+			"group": {
+				"kind": "build",
+				"isDefault": true
+			}
+		},
 		{
 			"type": "npm",
 			"script": "kill-watchd",

package.json

@@ -22,7 +22,9 @@
     "restart-watchd": "deemon --restart yarn watch",
     "restart-watch-webd": "deemon --restart yarn watch-web",
     "watch-client": "gulp watch-client --max_old_space_size=4095",
+    "watch-clientd": "deemon yarn watch-client",
     "watch-extensions": "gulp watch-extensions --max_old_space_size=4095",
+    "watch-extensionsd": "deemon yarn watch-extensions",
     "mocha": "mocha test/unit/node/all.js --delay",
     "precommit": "node build/gulpfile.hygiene.js",
     "gulp": "gulp --max_old_space_size=8192",