Provide better diagnostic wording for initializers on static
data member definitions when the variable has an initializer
in its declaration.

For the following code:

  struct S {
    static const int x = 42;
  };
  const int S::x = 42;

This patch changes the diagnostic from:

  a.cc:4:14: error: redefinition of 'x'
  const int S::x = 42;
               ^
  a.cc:2:20: note: previous definition is here
    static const int x = 42;
                     ^
to:

  a.cc:4:18: error: static data member 'x' already has an initializer
  const int S::x = 42;
                   ^
  a.cc:2:24: note: previous initialization is here
    static const int x = 42;
                         ^

Differential Revision: http://llvm-reviews.chandlerc.com/D2235

llvm-svn: 195306
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index cd64311..6d5e0f0 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -8184,9 +8184,9 @@
     // data members we also need to check whether there was an in-class
     // declaration with an initializer.
     if (VDecl->isStaticDataMember() && VDecl->getAnyInitializer(PrevInit)) {
-      Diag(VDecl->getLocation(), diag::err_redefinition) 
-        << VDecl->getDeclName();
-      Diag(PrevInit->getLocation(), diag::note_previous_definition);
+      Diag(Init->getExprLoc(), diag::err_static_data_member_reinitialization)
+          << VDecl->getDeclName();
+      Diag(PrevInit->getInit()->getExprLoc(), diag::note_previous_initializer) << 0;
       return;
     }