[dv regr tool] Updates to support LSF

- Update to move all tool sources to scratch area before build/run
- Added necessary build opts that are required for running VCS on Google
machines

Signed-off-by: Srikrishna Iyer <sriyer@google.com>
diff --git a/util/dvsim/SimCfg.py b/util/dvsim/SimCfg.py
index 6001c43..8849436 100644
--- a/util/dvsim/SimCfg.py
+++ b/util/dvsim/SimCfg.py
@@ -409,11 +409,16 @@
         testplan = testplan.replace("/dv", "/doc/dv_plan/#testplan")
         results_str += "### [Testplan](" + testplan + ")\n\n"
 
-        # TODO: check if testplan is not null?
-        results_str += self.testplan.results_table(
-            regr_results=regr_results,
-            map_full_testplan=self.map_full_testplan)
-        results_str += "\n"
+        if regr_results == []:
+            results_str += "No results to display.\n"
+
+        else:
+            # TODO: check if testplan is not null?
+            # Map regr results to the testplan entries.
+            results_str += self.testplan.results_table(
+                regr_results=regr_results,
+                map_full_testplan=self.map_full_testplan)
+            results_str += "\n"
 
         # Append failures for triage
         self.results_md = results_str + fail_msgs