Revert r195526, "Remove uninstantiable constructor from DeclTemplate.h"

It apparently causes some versions of GCC to segfault.
http://bb.pgr.jp/builders/cmake-clang-x86_64-linux/builds/17175/steps/build_clang/logs/stdio

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@195529 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/AST/DeclTemplate.h b/include/clang/AST/DeclTemplate.h
index 8fb4957b0b899c5a35df131f45a7a3c9f4678cee..4497197592cd2c03f6faa4d4625d706b9e273906 100644 (file)
--- a/include/clang/AST/DeclTemplate.h
+++ b/include/clang/AST/DeclTemplate.h
@@ -564,6 +564,7 @@ protected:
     SetIteratorType SetIter;
 
   public:
+    SpecIterator() : SetIter() {}
     SpecIterator(SetIteratorType SetIter) : SetIter(SetIter) {}
 
     DeclType *operator*() const {