fixes #25340, propagatedType now finds the instantiated generic method's return type

pkg/analyzer/lib/src/generated/static_type_analyzer.dart

Index: pkg/analyzer/lib/src/generated/static_type_analyzer.dart
diff --git a/pkg/analyzer/lib/src/generated/static_type_analyzer.dart b/pkg/analyzer/lib/src/generated/static_type_analyzer.dart
index fdda79a83b6a617b25e2b48f3238eafa459ba8a8..a034cbb3007b3cf5c624ff85b2c89e6b1c1062f3 100644
--- a/pkg/analyzer/lib/src/generated/static_type_analyzer.dart
+++ b/pkg/analyzer/lib/src/generated/static_type_analyzer.dart
@@ -873,16 +873,21 @@ class StaticTypeAnalyzer extends SimpleAstVisitor<Object> {
     }
     if (needPropagatedType) {
       Element propagatedElement = methodNameNode.propagatedElement;
+      DartType propagatedInvokeType = node.propagatedInvokeType;
       // HACK: special case for object methods ([toString]) on dynamic
       // expressions. More special cases in [visitPrefixedIdentfier].
       if (propagatedElement == null) {
-        propagatedElement =
+        MethodElement objMethod =
             _typeProvider.objectType.getMethod(methodNameNode.name);
+        if (objMethod != null) {
+          propagatedElement = objMethod;
+          propagatedInvokeType = objMethod.type;
+        }
       }
       if (!identical(propagatedElement, staticMethodElement)) {
         // Record static return type of the propagated element.
         DartType propagatedStaticType =
-            _computeStaticReturnType(propagatedElement);
+            _computeInvokeReturnType(propagatedInvokeType);
         _resolver.recordPropagatedTypeIfBetter(
             node, propagatedStaticType, true);
         // Record propagated return type of the propagated element.