Sema: Explain our deviation from the standard by referencing the, now open, LWG issue.

llvm-svn: 193062
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 176fe8a1c..e01c032 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -6807,6 +6807,8 @@
 
     // C++11 [replacement.functions]p3:
     //  The program's definitions shall not be specified as inline.
+    //
+    // N.B. We diagnose declarations instead of definitions per LWG issue 2340.
     if (isInline && NewFD->isReplaceableGlobalAllocationFunction())
       Diag(D.getDeclSpec().getInlineSpecLoc(),
            diag::err_operator_new_delete_declared_inline)