add dataflow support

Author: erik-krogh

javascript/ql/lib/semmle/javascript/dataflow/DataFlow.qll

@@ -1580,6 +1580,8 @@ module DataFlow {
       or
       predExpr = succExpr.(TypeAssertion).getExpression()
       or
+      predExpr = succExpr.(SatisfiesExpr).getExpression()
+      or
       predExpr = succExpr.(NonNullAssertion).getExpression()
       or
       predExpr = succExpr.(ExpressionWithTypeArguments).getExpression()

javascript/ql/test/library-tests/DataFlow/tests.expected

@@ -998,6 +998,7 @@ flowStep
 | tst2.ts:13:26:13:29 | List | tst2.ts:13:26:13:37 | List<string> |
 | tst2.ts:13:39:13:38 | args | tst2.ts:13:39:13:38 | args |
 | tst2.ts:13:39:13:38 | args | tst2.ts:13:39:13:38 | args |
+| tst2.ts:15:11:15:13 | A.x | tst2.ts:15:11:15:30 | A.x satisfies number |
 | tst.js:1:1:1:1 | x | tst.js:3:5:3:5 | x |
 | tst.js:1:10:1:11 | fs | tst.js:1:10:1:11 | fs |
 | tst.js:1:10:1:11 | fs | tst.js:7:1:7:2 | fs |
@@ -1184,6 +1185,7 @@ getImmediatePredecessor
 | tst2.ts:13:26:13:29 | List | tst2.ts:13:26:13:37 | List<string> |
 | tst2.ts:13:39:13:38 | args | tst2.ts:13:39:13:38 | args |
 | tst2.ts:13:39:13:38 | args | tst2.ts:13:39:13:38 | args |
+| tst2.ts:15:11:15:13 | A.x | tst2.ts:15:11:15:30 | A.x satisfies number |
 | tst.js:1:10:1:11 | fs | tst.js:1:10:1:11 | fs |
 | tst.js:1:10:1:11 | fs | tst.js:7:1:7:2 | fs |
 | tst.js:1:10:1:11 | fs | tst.js:22:24:22:25 | fs |