Use SwitchCase.getSelectorExpr

Author: smowton

java/ql/lib/semmle/code/java/controlflow/Guards.qll

@@ -108,8 +108,7 @@ class Guard extends ExprParent {
    */
   BasicBlock getBasicBlock() {
     result = this.(Expr).getBasicBlock() or
-    result = this.(SwitchCase).getSwitch().getExpr().getBasicBlock() or
-    result = this.(SwitchCase).getSwitchExpr().getExpr().getBasicBlock()
+    result = this.(SwitchCase).getSelectorExpr().getBasicBlock()
   }
 
   /**

java/ql/lib/semmle/code/java/dataflow/TypeFlow.qll

@@ -445,7 +445,7 @@ private predicate instanceOfGuarded(Expr e, RefType t) {
  */
 private predicate patternCaseGuarded(Expr e, RefType t) {
   exists(PatternCase pc |
-    e = getAProbableAlias([pc.getSwitch().getExpr(), pc.getSwitchExpr().getExpr()]) and
+    e = getAProbableAlias(pc.getSelectorExpr()) and
     guardControls_v1(pc, e.getBasicBlock(), true) and
     t = pc.getPattern().getType()
   )