[vm/aot/tfa] Speed up RTA on huge class hierarchies

Avoid iteration of all subtypes in RTA when adding selectors which are
already added. This is important when number of classes is very large
and hierarchy is very wide.

On a huge app (41K classes) RTA time 916723ms -> 56297ms (16x faster).

TEST=ci
Fixes b/322854909

Change-Id: I82b3094e09c010a20065cdde64dc3d7da9fe997a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/349143
Reviewed-by: Slava Egorov <[email protected]>
Commit-Queue: Alexander Markov <[email protected]>

Author: alexmarkov

pkg/vm/lib/transformations/type_flow/rta.dart

@@ -151,23 +151,27 @@ class _ClassHierarchyCache {
 
   void addDynamicCall(Selector selector, Class cl, RapidTypeAnalysis rta) {
     final ClassInfo classInfo = getClassInfo(cl);
-    for (var sub in classInfo.subtypes) {
-      if (sub.calledDynamicSelectors.add(selector) && sub.isAllocated) {
-        final member = sub.getDispatchTarget(selector);
-        if (member != null) {
-          rta.addMember(member);
+    if (!classInfo.calledDynamicSelectors.contains(selector)) {
+      for (var sub in classInfo.subtypes) {
+        if (sub.calledDynamicSelectors.add(selector) && sub.isAllocated) {
+          final member = sub.getDispatchTarget(selector);
+          if (member != null) {
+            rta.addMember(member);
+          }
         }
       }
     }
   }
 
   void addVirtualCall(Selector selector, Class cl, RapidTypeAnalysis rta) {
     final ClassInfo classInfo = getClassInfo(cl);
-    for (var sub in classInfo.subclasses) {
-      if (sub.calledVirtualSelectors.add(selector) && sub.isAllocated) {
-        final member = sub.getDispatchTarget(selector);
-        if (member != null) {
-          rta.addMember(member);
+    if (!classInfo.calledVirtualSelectors.contains(selector)) {
+      for (var sub in classInfo.subclasses) {
+        if (sub.calledVirtualSelectors.add(selector) && sub.isAllocated) {
+          final member = sub.getDispatchTarget(selector);
+          if (member != null) {
+            rta.addMember(member);
+          }
         }
       }
     }