Initial, rudimentary implementation of operator overloading for binary
operators. For example, one can now write "x + y" where x or y is a
class or enumeration type, and Clang will perform overload resolution
for "+" based on the overloaded operators it finds.

The other kinds of overloadable operators in C++ will follow this same
approach. 

Three major issues remain:
  1) We don't find member operators
  2) Since we don't have user-defined conversion operators, we can't
  call any of the built-in overloaded operators in C++ [over.built].
  3) Once we've done the semantic checks, we drop the overloaded
  operator on the floor; it doesn't get into the AST at all.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@58821 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/SemaCXX/overloaded-operator.cpp b/test/SemaCXX/overloaded-operator.cpp
new file mode 100644
index 0000000..52d31c0
--- /dev/null
+++ b/test/SemaCXX/overloaded-operator.cpp
@@ -0,0 +1,30 @@
+// RUN: clang -fsyntax-only -verify %s 
+class X { };
+
+X operator+(X, X);
+
+void f(X x) {
+  x = x + x;
+}
+
+struct Y;
+struct Z;
+
+struct Y {
+  Y(const Z&);
+};
+
+struct Z {
+  Z(const Y&);
+};
+
+Y operator+(Y, Y);
+bool operator-(Y, Y); // expected-note{{candidate function}}
+bool operator-(Z, Z); // expected-note{{candidate function}}
+
+void g(Y y, Z z) {
+  y = y + z;
+  bool b = y - z; // expected-error{{use of overloaded operator '-' is ambiguous; candidates are:}}
+}
+
+