JS: Add self as global object alias

javascript/ql/src/semmle/javascript/dataflow/Nodes.qll

@@ -304,6 +304,9 @@ DataFlow::SourceNode globalObjectRef() {
   // Node.js
   result = globalVarRef("global")
   or
+  // DOM and service workers
+  result = globalVarRef("self")
+  or
   // `require("global")`
   result = moduleImport("global")
   or

javascript/ql/test/library-tests/Nodes/globalObjectRef.expected

@@ -10,3 +10,4 @@
 | tst.js:3:1:3:6 | window |
 | tst.js:4:1:4:6 | window |
 | tst.js:4:1:4:13 | window.window |
+| tst.js:5:1:5:4 | self |

javascript/ql/test/library-tests/Nodes/globalVarRef.expected

@@ -3,11 +3,13 @@
 | document | tst2.js:2:1:2:26 | require ... ument") |
 | document | tst.js:3:1:3:15 | window.document |
 | document | tst.js:4:1:4:22 | window. ... ocument |
+| document | tst.js:5:1:5:13 | self.document |
 | foo | tst3.js:4:1:4:5 | w.foo |
 | global | tst2.js:7:1:7:6 | global |
 | global | tst2.js:8:1:8:6 | global |
 | goog | tst3.js:1:1:1:4 | goog |
 | goog | tst3.js:3:9:3:12 | goog |
+| self | tst.js:5:1:5:4 | self |
 | setTimeout | tst2.js:5:1:5:12 | g.setTimeout |
 | window | tst2.js:3:1:3:24 | require ... indow") |
 | window | tst.js:1:1:1:6 | window |

javascript/ql/test/library-tests/Nodes/tst.js

@@ -2,3 +2,4 @@ window;
 this;
 window.document;
 window.window.document;
+self.document;