Merge pull request github#356 from github/jsinglet/release-mutex

Fixes a locking order issue in the Matrix testing

Author: jsinglet

scripts/matrix_testing/CreateMatrixTestReport.ps1

@@ -417,16 +417,18 @@ $jobRows = $queriesToCheck | ForEach-Object -ThrottleLimit $NumThreads -Parallel
             # output current row state 
             $row 
 
-            # release any held mutexes            
-            $Mutex.ReleaseMutex();
-
+            
             ###########################################################
             ###########################################################
             # Context is restored here
             ###########################################################
             if($context){
                 Pop-CompilerSpecificFiles -Context $context 
             }
+
+            # release any held mutexes            
+            $Mutex.ReleaseMutex();
+            Write-Host "Released $testDirectory"
         }
     }
     # go to next row