Forbid 'in' operator on depset with --incompatible_depset_is_not_iterable

RELNOTES: None.
PiperOrigin-RevId: 159948522

src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java

diff --git a/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java b/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
index e6224fa..4a1d6a3 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
@@ -884,6 +884,7 @@
     new SkylarkTest("--incompatible_depset_is_not_iterable=true")
         .testIfErrorContains("not iterable", "list(depset(['a', 'b']))")
         .testIfErrorContains("not iterable", "max(depset([1, 2, 3]))")
+        .testIfErrorContains("not iterable", "1 in depset([1, 2, 3])")
         .testIfErrorContains("not iterable", "sorted(depset(['a', 'b']))")
         .testIfErrorContains("not iterable", "tuple(depset(['a', 'b']))")
         .testIfErrorContains("not iterable", "[x for x in depset()]")
@@ -895,6 +896,7 @@
     new SkylarkTest("--incompatible_depset_is_not_iterable=false")
         .testStatement("str(list(depset(['a', 'b'])))", "[\"a\", \"b\"]")
         .testStatement("max(depset([1, 2, 3]))", 3)
+        .testStatement("1 in depset([1, 2, 3])", true)
         .testStatement("str(sorted(depset(['b', 'a'])))", "[\"a\", \"b\"]")
         .testStatement("str(tuple(depset(['a', 'b'])))", "(\"a\", \"b\")")
         .testStatement("str([x for x in depset()])", "[]")