[element model] migrate test_types_in_equals

Bug: https://github.com/dart-lang/linter/issues/5099
Change-Id: I454fac69834b9616387520166f36780ee39e3bc9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/389421
Commit-Queue: Phil Quitslund <[email protected]>
Reviewed-by: Konstantin Shcheglov <[email protected]>

Author: pq

pkg/linter/lib/src/rules/test_types_in_equals.dart

@@ -41,7 +41,7 @@ class _Visitor extends SimpleAstVisitor<void> {
     }
 
     var parameters = declaration?.parameters;
-    var parameterName = parameters?.parameterElements.first?.name;
+    var parameterName = parameters?.parameterFragments.first?.name;
     if (expression.name == parameterName) {
       var typeName = _getTypeName(declaration!);
       rule.reportLint(node, arguments: [typeName]);
@@ -68,5 +68,5 @@ class _Visitor extends SimpleAstVisitor<void> {
       declaration != null &&
       declaration.isOperator &&
       declaration.name.lexeme == '==' &&
-      declaration.parameters?.parameterElements.length == 1;
+      declaration.parameters?.parameterFragments.length == 1;
 }