Abstract out the emission of vtables, add basic support for vtable emission when using -cxx-abi microsoft

Reviewed at http://llvm-reviews.chandlerc.com/D1532

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@191523 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 5e3d382..61ce344 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -1053,7 +1053,11 @@
 
     // It doesn't make sense to give a virtual destructor a vtable index,
     // since a single destructor has two entries in the vtable.
-    if (!isa<CXXDestructorDecl>(Method))
+    // FIXME: Add proper support for debug info for virtual calls in
+    // the Microsoft ABI, where we may use multiple vptrs to make a vftable
+    // lookup if we have multiple or virtual inheritance.
+    if (!isa<CXXDestructorDecl>(Method) &&
+        !CGM.getTarget().getCXXABI().isMicrosoft())
       VIndex = CGM.getVTableContext().getMethodVTableIndex(Method);
     ContainingType = RecordTy;
   }