Log Throwables that happened during the build to the outErr of the BlazeCommandDispatcher. This way they can be logged in the BEP.

PiperOrigin-RevId: 213998158
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java b/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java
index 99bbd81..9bc6c4a 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java
@@ -491,6 +491,9 @@
       }
       return result;
     } catch (Throwable e) {
+      outErr.printErr(
+          "Internal error thrown during build. Printing stack trace: "
+              + Throwables.getStackTraceAsString(e));
       e.printStackTrace();
       BugReport.printBug(outErr, e);
       BugReport.sendBugReport(e, args, env.getCrashData());