Mention that the STL doesn't throw domain_error or underflow_error.

Author: StephanTLavavej

docs/standard-library/domain-error-class.md

@@ -26,6 +26,8 @@ public:
 
 The value returned by `what()` is a copy of `message.data()`. For more information, see [`what`](../standard-library/exception-class.md) and [`data`](../standard-library/basic-string-class.md#data).
 
+`domain_error` isn't thrown by any functions in Microsoft's implementation of the C++ Standard Library, but may be thrown by third-party libraries or user code.
+
 ## Example
 
 ```cpp

docs/standard-library/underflow-error-class.md

@@ -26,6 +26,8 @@ public:
 
 The value returned by `what()` is a copy of `message.data()`. For more information, see [`what`](../standard-library/exception-class.md) and [`data`](../standard-library/basic-string-class.md#data).
 
+`underflow_error` isn't thrown by any functions in Microsoft's implementation of the C++ Standard Library, but may be thrown by third-party libraries or user code.
+
 ## Example
 
 ```cpp