SoftwareSerial examples for Arduino M0 will not compile

IDE: 1.8.2
Installation: C:\Program Files (x86)\Arduino\portable\packages\arduino\hardware\samd\1.6.15\libraries\SoftwareSerial\SoftwareSerial.cpp and \SoftwareSerial.h (from github from samd hardware)

Application : SoftwareSerialExample.ino (the original example)

Errors:
```
sketch\SoftwareSerial.cpp: In member function 'void SoftwareSerial::setTX(uint8_t)':

SoftwareSerial.cpp:174: error: cannot convert 'volatile uint32_t* {aka volatile long unsigned int*}' to 'volatile PORT_OUT_Type*' in assignment

_transmitPortRegister = portOutputRegister(port);

^

sketch\SoftwareSerial.cpp: In member function 'void SoftwareSerial::setRX(uint8_t)':

SoftwareSerial.cpp:186: error: cannot convert 'volatile uint32_t* {aka volatile long unsigned int*}' to 'volatile PORT_IN_Type*' in assignment

_receivePortRegister = portInputRegister(port);

^

exit status 1
cannot convert 'volatile uint32_t* {aka volatile long unsigned int*}' to 'volatile PORT_OUT_Type*' in assignment
```

What is wrong in the data type/ struc/?? that breaks this function? Attempted to port srv code base to samd base and the broken samd version does not work for serial I/O. Does anyone have a working example or modified .cpp / .h set that works?

Start with SoftwareSerial.cpp and SoftwareSerial.h from the SAMD hardware library, focusing on setTX and setRX and the reported register assignment errors. Reproduce the build with SoftwareSerialExample.ino in Arduino IDE 1.8.2; done means the example compiles for the Arduino M0 and supports the reported serial I/O path.

Written by the indexing model from the issue text.