Fix product name in directory messages

If bazel runs under emacs, it emits messages about changing
of directories.  In those messages, fix the product name.

Change-Id: I233a46db741dc4cd0dc5bfbaadbf2ad09c04952e
PiperOrigin-RevId: 165159721

src/main/java/com/google/devtools/build/lib/buildtool/ExecutionTool.java

@@ -403,7 +403,10 @@ void executeBuild(UUID buildId, AnalysisResult analysisResult,
 
     if (request.isRunningInEmacs()) {
       // The syntax of this message is tightly constrained by lisp/progmodes/compile.el in emacs
-      request.getOutErr().printErrLn("blaze: Entering directory `" + getExecRoot() + "/'");
+      request
+          .getOutErr()
+          .printErrLn(
+              env.getRuntime().getProductName() + ": Entering directory `" + getExecRoot() + "/'");
     }
     boolean buildCompleted = false;
     try {
@@ -445,7 +448,10 @@ void executeBuild(UUID buildId, AnalysisResult analysisResult,
     } finally {
       env.recordLastExecutionTime();
       if (request.isRunningInEmacs()) {
-        request.getOutErr().printErrLn("blaze: Leaving directory `" + getExecRoot() + "/'");
+        request
+            .getOutErr()
+            .printErrLn(
+                env.getRuntime().getProductName() + ": Leaving directory `" + getExecRoot() + "/'");
       }
       if (buildCompleted) {
         getReporter().handle(Event.progress("Building complete."));