The great Skylark -> Starlark class migration:
  SkylarkRuleClassSerializer
  SkylarkProviderIdentifierCodecTest
  SkylarkProviderIdentifier

Rough algorithm:
 - Convert these class names
 - Convert methods, variables, other symbols encountered in the files these
 classes are defined in.
- *Don't* replace class names for classes defined in other files. These will
 be handled in their own order. This helps keep individual changelist scope
 small.

PiperOrigin-RevId: 307063447
diff --git a/src/main/java/com/google/devtools/build/lib/packages/BuiltinProvider.java b/src/main/java/com/google/devtools/build/lib/packages/BuiltinProvider.java
index 4a96dad..16c0892 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/BuiltinProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/BuiltinProvider.java
@@ -99,10 +99,8 @@
     throw Starlark.errorf("'%s' cannot be constructed from Starlark", getPrintableName());
   }
 
-  /**
-   * Returns the identifier of this provider.
-   */
-  public SkylarkProviderIdentifier id() {
-    return SkylarkProviderIdentifier.forKey(getKey());
+  /** Returns the identifier of this provider. */
+  public StarlarkProviderIdentifier id() {
+    return StarlarkProviderIdentifier.forKey(getKey());
   }
 }