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/Sema.h b/lib/Sema/Sema.h
index 2ed90d0..b193688 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -725,9 +725,9 @@
                   OverloadedFunctionDecl::function_iterator &MatchedDecl);
   ImplicitConversionSequence 
   TryImplicitConversion(Expr* From, QualType ToType,
-                        bool SuppressUserConversions = false,
-                        bool AllowExplicit = false,
-                        bool ForceRValue = false);
+                        bool SuppressUserConversions,
+                        bool AllowExplicit,
+                        bool ForceRValue);
   bool IsStandardConversion(Expr *From, QualType ToType, 
                             StandardConversionSequence& SCS);
   bool IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType);