Remove default arguments from TryImplicitConversion and fix a bug found in the process.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@80258 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaCXXCast.cpp b/lib/Sema/SemaCXXCast.cpp
index 17fe940..3643b88 100644
--- a/lib/Sema/SemaCXXCast.cpp
+++ b/lib/Sema/SemaCXXCast.cpp
@@ -788,8 +788,12 @@
   // reimplement more of this.
   // FIXME: This does not actually perform the conversion, and thus does not
   // check for ambiguity or access.
-  ImplicitConversionSequence ICS = Self.TryImplicitConversion(
-    SrcExpr, DestType);
+  ImplicitConversionSequence ICS = 
+    Self.TryImplicitConversion(SrcExpr, DestType,
+                               /*SuppressUserConversions=*/false,
+                               /*AllowExplicit=*/false,
+                               /*ForceRValue=*/false);
+  
   if (ICS.ConversionKind  == ImplicitConversionSequence::UserDefinedConversion)
     if (CXXConversionDecl *CV = 
           dyn_cast<CXXConversionDecl>(ICS.UserDefined.ConversionFunction))