Add mangling for variadic functions and conversion functions

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64425 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/overloadable.c b/test/CodeGen/overloadable.c
index 6b1cb35..4e24c91 100644
--- a/test/CodeGen/overloadable.c
+++ b/test/CodeGen/overloadable.c
@@ -9,6 +9,8 @@
 struct X { };
 void  __attribute__((overloadable)) f(struct X (*ptr)[10]) { }
 
+void __attribute__((overloadable)) f(int x, int y, ...) { }
+
 int main() {
   int iv = 17;
   float fv = 3.0f;