Disable the 'default' parameter of attr.output and attr.output_list

This is attached to a new Starlark semantics flag, --incompatible_no_output_attr_default

RELNOTES: The 'default' parameter of attr.output and attr.output_list is removed. This is controlled by --incompatible_no_output_attr_default
PiperOrigin-RevId: 215805602
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 9805d61..bad29a9 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
@@ -131,6 +131,8 @@
 
   public abstract boolean incompatibleNewActionsApi();
 
+  public abstract boolean incompatibleNoOutputAttrDefault();
+
   public abstract boolean incompatibleNoSupportToolsInActionInputs();
 
   public abstract boolean incompatibleNoTargetOutputGroup();
@@ -188,6 +190,7 @@
           .incompatibleExpandDirectories(false)
           .incompatibleGenerateJavaCommonSourceJar(false)
           .incompatibleNewActionsApi(false)
+          .incompatibleNoOutputAttrDefault(false)
           .incompatibleNoSupportToolsInActionInputs(false)
           .incompatibleNoTargetOutputGroup(false)
           .incompatibleNoTransitiveLoads(false)
@@ -246,6 +249,8 @@
 
     public abstract Builder incompatibleNewActionsApi(boolean value);
 
+    public abstract Builder incompatibleNoOutputAttrDefault(boolean value);
+
     public abstract Builder incompatibleNoSupportToolsInActionInputs(boolean value);
 
     public abstract Builder incompatibleNoTargetOutputGroup(boolean value);