Add the ability to determine whether a format string argument is of a double...

Add the ability to determine whether a format string argument is of a double type or not. This change is tested by clang-tidy in r268100.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@268103 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Analysis/Analyses/FormatString.h

@@ -216,6 +216,10 @@ public:
     kind == FreeBSDrArg || kind == FreeBSDyArg; }
   bool isUIntArg() const { return kind >= UIntArgBeg && kind <= UIntArgEnd; }
   bool isAnyIntArg() const { return kind >= IntArgBeg && kind <= UIntArgEnd; }
+  bool isDoubleArg() const {
+    return kind >= DoubleArgBeg && kind <= DoubleArgEnd;
+  }
+
   const char *toString() const;
 
   bool isPrintfKind() const { return IsPrintf; }