Implement testing::Rethrow to throw exceptions more easily via std::exception_ptr

We avoid overloading or specializing `testing::Throw` as this is fundamentally a different operation than throwing the object.
However, we disable the corresponding overload of `testing::Throw` to prevent likely mistakes in the usage.

Fixes: #4412
PiperOrigin-RevId: 585745469
Change-Id: I03bb585427ce51983d914e88f2bf65a13545c920

googlemock/test/gmock_link_test.h

@@ -187,6 +187,7 @@ using testing::SetErrnoAndReturn;
 
 #if GTEST_HAS_EXCEPTIONS
 using testing::Throw;
+using testing::Rethrow;
 #endif
 
 using testing::ContainsRegex;
@@ -416,6 +417,14 @@ TEST(LinkTest, TestThrow) {
   EXPECT_CALL(mock, VoidFromString(_)).WillOnce(Throw(42));
   EXPECT_THROW(mock.VoidFromString(nullptr), int);
 }
+// Tests the linkage of the Rethrow action.
+TEST(LinkTest, TestRethrow) {
+  Mock mock;
+
+  EXPECT_CALL(mock, VoidFromString(_))
+      .WillOnce(Rethrow(std::make_exception_ptr(42)));
+  EXPECT_THROW(mock.VoidFromString(nullptr), int);
+}
 #endif  // GTEST_HAS_EXCEPTIONS
 
 // The ACTION*() macros trigger warning C4100 (unreferenced formal