Rename some functions for consistency.

Every other function in Redeclarable.h was using Decl instead of Declaration.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192900 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 655c9e2..bd864b3 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -7840,7 +7840,7 @@
     if (Invalid)
       NewDecl->setInvalidDecl();
     else if (OldDecl)
-      NewDecl->setPreviousDeclaration(OldDecl);
+      NewDecl->setPreviousDecl(OldDecl);
 
     NewND = NewDecl;
   } else {