Unifies the name-lookup mechanisms used in various parts of the AST
and separates lexical name lookup from qualified name lookup. In
particular:
  * Make DeclContext the central data structure for storing and
    looking up declarations within existing declarations, e.g., members
    of structs/unions/classes, enumerators in C++0x enums, members of
    C++ namespaces, and (later) members of Objective-C
    interfaces/implementations. DeclContext uses a lazily-constructed
    data structure optimized for fast lookup (array for small contexts,
    hash table for larger contexts). 

  * Implement C++ qualified name lookup in terms of lookup into
    DeclContext.

  * Implement C++ unqualified name lookup in terms of
    qualified+unqualified name lookup (since unqualified lookup is not
    purely lexical in C++!)

  * Limit the use of the chains of declarations stored in
    IdentifierInfo to those names declared lexically.

  * Eliminate CXXFieldDecl, collapsing its behavior into
    FieldDecl. (FieldDecl is now a ScopedDecl).

  * Make RecordDecl into a DeclContext and eliminates its
    Members/NumMembers fields (since one can just iterate through the
    DeclContext to get the fields).



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@60878 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 341baea..7a83d6c 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -156,9 +156,11 @@
   FieldDecl *FD = E->getMemberDecl();
     
   // FIXME: This is linear time.
-  unsigned i = 0, e = 0;
-  for (i = 0, e = RD->getNumMembers(); i != e; i++) {
-    if (RD->getMember(i) == FD)
+  unsigned i = 0;
+  for (RecordDecl::field_iterator Field = RD->field_begin(),
+                               FieldEnd = RD->field_end();
+       Field != FieldEnd; (void)++Field, ++i) {
+    if (*Field == FD)
       break;
   }