Reapply r183721, reverted in r183776, with a fix for a bug in the former (we
were lacking ExprWithCleanups nodes in some cases where the new approach to
lifetime extension needed them).

Original commit message:

Rework IR emission for lifetime-extended temporaries. Instead of trying to walk
into the expression and dig out a single lifetime-extended entity and manually
pull its cleanup outside the expression, instead keep a list of the cleanups
which we'll need to emit when we get to the end of the full-expression. Also
emit those cleanups early, as EH-only cleanups, to cover the case that the
full-expression does not terminate normally. This allows IR generation to
properly model temporary lifetime when multiple temporaries are extended by the
same declaration.

We have a pre-existing bug where an exception thrown from a temporary's
destructor does not clean up lifetime-extended temporaries created in the same
expression and extended to automatic storage duration; that is not fixed by
this patch.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183859 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index b1c0f56..008bb73 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -2579,6 +2579,8 @@
     if (MemberInit.isInvalid())
       return true;
 
+    CheckForDanglingReferenceOrPointer(*this, Member, MemberInit.get(), IdLoc);
+
     // C++11 [class.base.init]p7:
     //   The initialization of each base and member constitutes a
     //   full-expression.
@@ -2587,7 +2589,6 @@
       return true;
 
     Init = MemberInit.get();
-    CheckForDanglingReferenceOrPointer(*this, Member, Init, IdLoc);
   }
 
   if (DirectMember) {