Increase npm run watch/compile max RAM to 4gb

Node defaults to a limit of 1.7gb apparently, this causes issues particularly
on Windows where it's easy to hit this limit. This change rolls the limit
adjustment into npm run watch and npm run compile.

Fixes #7108

package.json

@@ -12,8 +12,8 @@
     "test": "mocha",
     "preinstall": "node build/npm/preinstall.js",
     "postinstall": "node build/npm/postinstall.js",
-    "compile": "gulp compile",
-    "watch": "gulp watch",
+    "compile": "gulp compile --max-old-space-size=4096",
+    "watch": "gulp watch --max-old-space-size=4096",
     "monaco-editor-setup": "node scripts/monaco-editor-setup.js",
     "monaco-editor-test": "mocha --only-monaco-editor"
   },