Introduce basic ASTs for lambda expressions. This covers:
  - Capturing variables by-reference and by-copy within a lambda
  - The representation of lambda captures
  - The creation of the non-static data members in the lambda class
  that store the captured variables
  - The initialization of the non-static data members from the
  captured variables
  - Pretty-printing lambda expressions

There are a number of FIXMEs, both explicit and implied, including:
  - Creating a field for a capture of 'this'
  - Improved diagnostics for initialization failures when capturing
  variables by copy
  - Dealing with temporaries created during said initialization
  - Template instantiation
  - AST (de-)serialization
  - Binding and returning the lambda expression; turning it into a
  proper temporary
  - Lots and lots of semantic constraints
  - Parameter pack captures


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149977 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 8738e5f..f2ebd8c 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -2019,6 +2019,16 @@
     return MergeCanThrow(CT, CanSubExprsThrow(C, this));
   }
 
+  case LambdaExprClass: {
+    const LambdaExpr *Lambda = cast<LambdaExpr>(this);
+    CanThrowResult CT = Expr::CT_Cannot;
+    for (LambdaExpr::capture_init_iterator Cap = Lambda->capture_init_begin(),
+                                        CapEnd = Lambda->capture_init_end();
+         Cap != CapEnd; ++Cap)
+      CT = MergeCanThrow(CT, (*Cap)->CanThrow(C));
+    return CT;
+  }
+
   case CXXNewExprClass: {
     CanThrowResult CT;
     if (isTypeDependent())