Report a static warning if a for loop condition is non-boolean.

pkg/analyzer/test/generated/static_type_warning_code_test.dart

Index: pkg/analyzer/test/generated/static_type_warning_code_test.dart
diff --git a/pkg/analyzer/test/generated/static_type_warning_code_test.dart b/pkg/analyzer/test/generated/static_type_warning_code_test.dart
index 5f5d0ef7dd2f38381eb61562cb2e7c8434877b40..137deb568c5f5ebbfad901c3dba35f6892f86d74 100644
--- a/pkg/analyzer/test/generated/static_type_warning_code_test.dart
+++ b/pkg/analyzer/test/generated/static_type_warning_code_test.dart
@@ -703,6 +703,16 @@ f() {
     verify([source]);
   }
 
+  void test_nonBoolCondition_for() {
+    Source source = addSource(r'''
+f() {
+  for (;3;) {}
+}''');
+    computeLibrarySourceErrors(source);
+    assertErrors(source, [StaticTypeWarningCode.NON_BOOL_CONDITION]);
+    verify([source]);
+  }
+
   void test_nonBoolCondition_if() {
     Source source = addSource(r'''
 f() {