Improve output for failed wcsto* tests.

Bug: None
Test: ran these and finally understood which sub-test was failing
Change-Id: I51c6536eba4b9c82ed4b062b1702128e23cf339c
diff --git a/tests/wchar_test.cpp b/tests/wchar_test.cpp
index 9cef52c..4105c0d 100644
--- a/tests/wchar_test.cpp
+++ b/tests/wchar_test.cpp
@@ -543,8 +543,8 @@
 void TestSingleWcsToInt(WcsToIntFn<T> fn, const wchar_t* str, int base,
                         T expected_value, ptrdiff_t expected_len) {
   wchar_t* p;
-  ASSERT_EQ(expected_value, fn(str, &p, base));
-  ASSERT_EQ(expected_len, p - str) << str;
+  EXPECT_EQ(expected_value, fn(str, &p, base)) << str << " " << base;
+  EXPECT_EQ(expected_len, p - str) << str << " " << base;
 }
 
 template <typename T>