Remove support for the --incompatible_disallow_three_arg_vardef command line option.

It was used for a migration, which is now done.

RELNOTES: None.
PiperOrigin-RevId: 192246659
diff --git a/src/main/java/com/google/devtools/build/lib/packages/SkylarkSemanticsCodec.java b/src/main/java/com/google/devtools/build/lib/packages/SkylarkSemanticsCodec.java
index 43975c1..c2fa734 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/SkylarkSemanticsCodec.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/SkylarkSemanticsCodec.java
@@ -50,7 +50,6 @@
     codedOut.writeBoolNoTag(semantics.incompatibleDisableObjcProviderResources());
     codedOut.writeBoolNoTag(semantics.incompatibleDisallowDictPlus());
     codedOut.writeBoolNoTag(semantics.incompatibleDisallowOldStyleArgsAdd());
-    codedOut.writeBoolNoTag(semantics.incompatibleDisallowThreeArgVardef());
     codedOut.writeBoolNoTag(semantics.incompatibleDisallowToplevelIfStatement());
     codedOut.writeBoolNoTag(semantics.incompatibleNewActionsApi());
     codedOut.writeBoolNoTag(semantics.incompatiblePackageNameIsAFunction());
@@ -73,7 +72,6 @@
     builder.incompatibleDisableObjcProviderResources(codedIn.readBool());
     builder.incompatibleDisallowDictPlus(codedIn.readBool());
     builder.incompatibleDisallowOldStyleArgsAdd(codedIn.readBool());
-    builder.incompatibleDisallowThreeArgVardef(codedIn.readBool());
     builder.incompatibleDisallowToplevelIfStatement(codedIn.readBool());
     builder.incompatibleNewActionsApi(codedIn.readBool());
     builder.incompatiblePackageNameIsAFunction(codedIn.readBool());
diff --git a/src/main/java/com/google/devtools/build/lib/packages/SkylarkSemanticsOptions.java b/src/main/java/com/google/devtools/build/lib/packages/SkylarkSemanticsOptions.java
index d97cf33..38ca1d0 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/SkylarkSemanticsOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/SkylarkSemanticsOptions.java
@@ -160,19 +160,6 @@
   public boolean incompatibleDisallowOldStyleArgsAdd;
 
   @Option(
-    name = "incompatible_disallow_three_arg_vardef",
-    defaultValue = "false",
-    documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
-    effectTags = {OptionEffectTag.UNKNOWN},
-    metadataTags = {
-      OptionMetadataTag.INCOMPATIBLE_CHANGE,
-      OptionMetadataTag.TRIGGERED_BY_ALL_INCOMPATIBLE_CHANGES
-    },
-    help = "If set to true, three-argument `vardef()` functions are disallowed."
-  )
-  public boolean incompatibleDisallowThreeArgVardef;
-
-  @Option(
     name = "incompatible_disallow_toplevel_if_statement",
     defaultValue = "true",
     documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
@@ -282,7 +269,6 @@
         .incompatibleDisableObjcProviderResources(incompatibleDisableObjcProviderResources)
         .incompatibleDisallowDictPlus(incompatibleDisallowDictPlus)
         .incompatibleDisallowOldStyleArgsAdd(incompatibleDisallowOldStyleArgsAdd)
-        .incompatibleDisallowThreeArgVardef(incompatibleDisallowThreeArgVardef)
         .incompatibleDisallowToplevelIfStatement(incompatibleDisallowToplevelIfStatement)
         .incompatibleNewActionsApi(incompatibleNewActionsApi)
         .incompatiblePackageNameIsAFunction(incompatiblePackageNameIsAFunction)
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkSemantics.java b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkSemantics.java
index ea90d37..e0ef87f 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkSemantics.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkSemantics.java
@@ -53,8 +53,6 @@
 
   public abstract boolean incompatibleDisallowOldStyleArgsAdd();
 
-  public abstract boolean incompatibleDisallowThreeArgVardef();
-
   public abstract boolean incompatibleDisallowToplevelIfStatement();
 
   public abstract boolean incompatibleNewActionsApi();
@@ -91,7 +89,6 @@
           .incompatibleDisableObjcProviderResources(false)
           .incompatibleDisallowDictPlus(false)
           .incompatibleDisallowOldStyleArgsAdd(false)
-          .incompatibleDisallowThreeArgVardef(false)
           .incompatibleDisallowToplevelIfStatement(true)
           .incompatibleNewActionsApi(false)
           .incompatiblePackageNameIsAFunction(false)
@@ -120,8 +117,6 @@
 
     public abstract Builder incompatibleDisallowOldStyleArgsAdd(boolean value);
 
-    public abstract Builder incompatibleDisallowThreeArgVardef(boolean value);
-
     public abstract Builder incompatibleDisallowToplevelIfStatement(boolean value);
 
     public abstract Builder incompatibleNewActionsApi(boolean value);
diff --git a/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java b/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java
index 4256ab8..6c4a34e 100644
--- a/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java
+++ b/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java
@@ -126,7 +126,6 @@
         "--incompatible_disable_objc_provider_resources=" + rand.nextBoolean(),
         "--incompatible_disallow_dict_plus=" + rand.nextBoolean(),
         "--incompatible_disallow_old_style_args_add=" + rand.nextBoolean(),
-        "--incompatible_disallow_three_arg_vardef=" + rand.nextBoolean(),
         "--incompatible_disallow_toplevel_if_statement=" + rand.nextBoolean(),
         "--incompatible_new_actions_api=" + rand.nextBoolean(),
         "--incompatible_package_name_is_a_function=" + rand.nextBoolean(),
@@ -150,7 +149,6 @@
         .incompatibleDisableObjcProviderResources(rand.nextBoolean())
         .incompatibleDisallowDictPlus(rand.nextBoolean())
         .incompatibleDisallowOldStyleArgsAdd(rand.nextBoolean())
-        .incompatibleDisallowThreeArgVardef(rand.nextBoolean())
         .incompatibleDisallowToplevelIfStatement(rand.nextBoolean())
         .incompatibleNewActionsApi(rand.nextBoolean())
         .incompatiblePackageNameIsAFunction(rand.nextBoolean())