Rework base and member initialization in constructors, with several
(necessarily simultaneous) changes:

  - CXXBaseOrMemberInitializer now contains only a single initializer
    rather than a set of initialiation arguments + a constructor. The
    single initializer covers all aspects of initialization, including
    constructor calls as necessary but also cleanup of temporaries
    created by the initializer (which we never handled
    before!).

  - Rework + simplify code generation for CXXBaseOrMemberInitializers,
    since we can now just emit the initializer as an initializer.

  - Switched base and member initialization over to the new
    initialization code (InitializationSequence), so that it

  - Improved diagnostics for the new initialization code when
    initializing bases and members, to match the diagnostics produced
    by the previous (special-purpose) code.

  - Simplify the representation of type-checked constructor initializers in
    templates; instead of keeping the fully-type-checked AST, which is
    rather hard to undo at template instantiation time, throw away the
    type-checked AST and store the raw expressions in the AST. This
    simplifies instantiation, but loses a little but of information in
    the AST.

  - When type-checking implicit base or member initializers within a
    dependent context, don't add the generated initializers into the
    AST, because they'll look like they were explicit.

  - Record in CXXConstructExpr when the constructor call is to
  initialize a base class, so that CodeGen does not have to infer it
  from context. This ensures that we call the right kind of
  constructor.

There are also a few "opportunity" fixes here that were needed to not
regress, for example:

  - Diagnose default-initialization of a const-qualified class that
    does not have a user-declared default constructor. We had this
    diagnostic specifically for bases and members, but missed it for
    variables. That's fixed now.

  - When defining the implicit constructors, destructor, and
    copy-assignment operator, set the CurContext to that constructor
    when we're defining the body.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@94952 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ExprCXX.cpp b/lib/AST/ExprCXX.cpp
index 3931bbd..70d0891 100644
--- a/lib/AST/ExprCXX.cpp
+++ b/lib/AST/ExprCXX.cpp
@@ -424,22 +424,26 @@
                                            SourceLocation Loc,
                                            CXXConstructorDecl *D, bool Elidable,
                                            Expr **Args, unsigned NumArgs,
-                                           bool ZeroInitialization) {
+                                           bool ZeroInitialization,
+                                           bool BaseInitialization) {
   return new (C) CXXConstructExpr(C, CXXConstructExprClass, T, Loc, D, 
-                                  Elidable, Args, NumArgs, ZeroInitialization);
+                                  Elidable, Args, NumArgs, ZeroInitialization,
+                                  BaseInitialization);
 }
 
 CXXConstructExpr::CXXConstructExpr(ASTContext &C, StmtClass SC, QualType T,
                                    SourceLocation Loc,
                                    CXXConstructorDecl *D, bool elidable,
                                    Expr **args, unsigned numargs,
-                                   bool ZeroInitialization)
+                                   bool ZeroInitialization,
+                                   bool BaseInitialization)
 : Expr(SC, T,
        T->isDependentType(),
        (T->isDependentType() ||
         CallExpr::hasAnyValueDependentArguments(args, numargs))),
   Constructor(D), Loc(Loc), Elidable(elidable), 
-  ZeroInitialization(ZeroInitialization), Args(0), NumArgs(numargs) 
+  ZeroInitialization(ZeroInitialization), 
+  BaseInitialization(BaseInitialization), Args(0), NumArgs(numargs) 
 {
   if (NumArgs) {
     Args = new (C) Stmt*[NumArgs];