[analyzer]scan-build: report the total number of steps analyzer performs

This would be useful to investigate performance issues.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159038 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/scan-build/ccc-analyzer b/tools/scan-build/ccc-analyzer
index 86a3616..b8f7193 100755
--- a/tools/scan-build/ccc-analyzer
+++ b/tools/scan-build/ccc-analyzer
@@ -438,6 +438,9 @@
 # Get the constraints engine.
 my $ConstraintsModel = $ENV{'CCC_ANALYZER_CONSTRAINTS_MODEL'};
 
+#Get the internal stats setting.
+my $InternalStats = $ENV{'CCC_ANALYZER_INTERNAL_STATS'};
+
 # Get the output format.
 my $OutputFormat = $ENV{'CCC_ANALYZER_OUTPUT_FORMAT'};
 if (!defined $OutputFormat) { $OutputFormat = "html"; }
@@ -642,6 +645,10 @@
     if (defined $ConstraintsModel) {
       push @AnalyzeArgs, "-analyzer-constraints=$ConstraintsModel";
     }
+
+    if (defined $InternalStats) {
+      push @AnalyzeArgs, "-analyzer-stats";
+    }
     
     if (defined $Analyses) {
       push @AnalyzeArgs, split '\s+', $Analyses;