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/Serialization/ASTWriterStmt.cpp b/lib/Serialization/ASTWriterStmt.cpp
index 3cfab77..c71d08e 100644
--- a/lib/Serialization/ASTWriterStmt.cpp
+++ b/lib/Serialization/ASTWriterStmt.cpp
@@ -1022,6 +1022,11 @@
   Code = serialization::EXPR_CXX_TEMPORARY_OBJECT;
 }
 
+void ASTStmtWriter::VisitLambdaExpr(LambdaExpr *E) {
+  VisitExpr(E);
+  assert(false && "Cannot serialize lambda expressions yet");
+}
+
 void ASTStmtWriter::VisitCXXNamedCastExpr(CXXNamedCastExpr *E) {
   VisitExplicitCastExpr(E);
   Writer.AddSourceRange(SourceRange(E->getOperatorLoc(), E->getRParenLoc()),