Delete redundant output file conflict logic

outputFilePrefixes is a map used to help check whether one OutputFile's name clashes with a directory prefix of another. Since it's updated with info from every OutputFile of a rule passed to checkForConflicts(), there's no need to also update it in addRuleUnchecked().

This is a no-op assuming that no user of Package.Builder calls both addRule() and addRuleUnchecked() -- which is currently the case, and ought to be enforced, perhaps in a follow-up CL.

(Note that the alternative approach, of deleting the map update in checkForConflicts() while leaving it intact in addRuleUnchecked(), is not only less readable, but also incorrect since it doesn't catch conflicts between OutputFiles of the same generating rule.)

Work toward #19922.

PiperOrigin-RevId: 595683434
Change-Id: I8b660807edfa1eef5101fe362ddaed4352e3f684

src/main/java/com/google/devtools/build/lib/packages/Package.java

@@ -1553,15 +1553,8 @@ void addEnvironmentGroup(
      */
     void addRuleUnchecked(Rule rule) {
       Preconditions.checkArgument(rule.getPackage() == pkg);
-      // Now, modify the package:
       for (OutputFile outputFile : rule.getOutputFiles()) {
         targets.put(outputFile.getName(), outputFile);
-        PathFragment outputFileFragment = PathFragment.create(outputFile.getName());
-        int segmentCount = outputFileFragment.segmentCount();
-        for (int i = 1; i < segmentCount; i++) {
-          String prefix = outputFileFragment.subFragment(0, i).toString();
-          outputFilePrefixes.putIfAbsent(prefix, outputFile);
-        }
       }
       targets.put(rule.getName(), rule);
       if (rule.containsErrors()) {