Fix json syntax in TotalConstraintStats.json (#605)

* Fix json syntax in TotalConstraintStats.json

An extra comma was added in this file when running 3c without -alltypes.
Also adds a test case that checks the syntax in all generated json files.

Author: john-h-kastner

clang/lib/3C/ProgramInfo.cpp

@@ -353,10 +353,11 @@ void ProgramInfo::printStats(const std::set<std::string> &F, raw_ostream &O,
       O << "\"BoundsStats\":";
     }
     ArrBInfo.printStats(O, InSrcCVars, JsonFormat);
+    if (JsonFormat)
+      O << ",";
   }
 
   if (JsonFormat) {
-    O << ",";
     O << "\"PerformanceStats\":";
   }
 

clang/test/3C/json_formating.c

@@ -0,0 +1,11 @@
+// RUN: 3c -base-dir=%S -alltypes -dump-stats -dump-intermediate -debug-solver %s
+// RUN: python -c "import json, glob; [json.load(open(f)) for f in glob.glob('*.json')]"
+// RUN: 3c -base-dir=%S -dump-stats -dump-intermediate -debug-solver %s
+// RUN: python -c "import json, glob; [json.load(open(f)) for f in glob.glob('*.json')]"
+
+// Testing that json files output for statistics logging are well formed
+
+int *a;
+int *b(int *c);
+static int *d() { return 0; }
+void e(int *f, int len) { f[0]; }