Fix redefinition of typedefs of fixable variably-modified array types; should
fix an issue compiling <windows.h>.

llvm-svn: 110651
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index e6c5170..d94b8dd3 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -2332,16 +2332,10 @@
   // Handle attributes prior to checking for duplicates in MergeVarDecl
   ProcessDeclAttributes(S, NewTD, D);
 
-  // Merge the decl with the existing one if appropriate. If the decl is
-  // in an outer scope, it isn't the same thing.
-  FilterLookupForScope(*this, Previous, DC, S, /*ConsiderLinkage*/ false);
-  if (!Previous.empty()) {
-    Redeclaration = true;
-    MergeTypeDefDecl(NewTD, Previous);
-  }
-
   // C99 6.7.7p2: If a typedef name specifies a variably modified type
   // then it shall have block scope.
+  // Note that variably modified types must be fixed before merging the decl so
+  // that redeclarations will match.
   QualType T = NewTD->getUnderlyingType();
   if (T->isVariablyModifiedType()) {
     setFunctionHasBranchProtectedScope();
@@ -2365,6 +2359,14 @@
     }
   }
 
+  // Merge the decl with the existing one if appropriate. If the decl is
+  // in an outer scope, it isn't the same thing.
+  FilterLookupForScope(*this, Previous, DC, S, /*ConsiderLinkage*/ false);
+  if (!Previous.empty()) {
+    Redeclaration = true;
+    MergeTypeDefDecl(NewTD, Previous);
+  }
+
   // If this is the C FILE type, notify the AST context.
   if (IdentifierInfo *II = NewTD->getIdentifier())
     if (!NewTD->isInvalidDecl() &&