Basic/Diagnostics: Eliminate getDiagnosticMappingInfo method, which wasn't worth methodizing.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@140759 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/DiagnosticIDs.cpp b/lib/Basic/DiagnosticIDs.cpp
index 1e76a26..d8a0afc 100644
--- a/lib/Basic/DiagnosticIDs.cpp
+++ b/lib/Basic/DiagnosticIDs.cpp
@@ -507,8 +507,7 @@
   DiagnosticsEngine::DiagState *State = Pos->State;
 
   // Get the mapping information, if unset, compute it lazily.
-  unsigned MappingInfo = Diag.getDiagnosticMappingInfo((diag::kind)DiagID,
-                                                       State);
+  unsigned MappingInfo = State->getMapping((diag::kind) DiagID);
   if (MappingInfo == 0) {
     MappingInfo = GetDefaultDiagMapping(DiagID);
     Diag.setDiagnosticMappingInternal(DiagID, MappingInfo, State, false, false);