Compilation errors when TX Buffer size is set greater than 0

[fkahhaleh]

Given that this is an older 1.1.9 release, I am not sure if I'll get any feedback but I thought it is worth a shot!

I am reviving an older machine running custom board and custom 1.1.8 firmware. I would like to recompile for 1.1.9 and
this repo shows the most potential! However part of their customization to their marlin is enabling TX_BUFFER_SIZE 128 instead of 0.

The printer heavily uses serial port communication with Marlin to issue commands. Once I made that change I could no longer compile the project. Thanks!

In file included from ../MarlinConfig.h:27:0,
from ../MarlinSerial.cpp:36:
../MarlinSerial.cpp: In function 'void _tx_udr_empty_irq()':
../macros.h:165:25: error: lvalue required as left operand of assignment
#define _BV(b) (1 << (b))
^
../macros.h:168:25: note: in expansion of macro '_BV'
#define CBI(n,b) (n &= ~_BV(b))
^~~
../MarlinSerial.cpp:352:9: note: in expansion of macro 'CBI'
CBI(M_UCSRxB, M_UDRIEx); // (Non-atomic, could be reenabled by the main program, but eventually this will succeed)
^~~
../MarlinSerial.cpp:359:16: error: lvalue required as left operand of assignment
M_UDRx = c;
^
In file included from ../MarlinConfig.h:27:0,
from ../MarlinSerial.cpp:36:
../macros.h:165:25: error: lvalue required as left operand of assignment
#define _BV(b) (1 << (b))
^
../macros.h:167:24: note: in expansion of macro '_BV'
#define SBI(n,b) (n |= _BV(b))
^~~
../MarlinSerial.cpp:364:7: note: in expansion of macro 'SBI'
SBI(M_UCSRxA, M_TXCx);
^~~
../macros.h:165:25: error: lvalue required as left operand of assignment
#define _BV(b) (1 << (b))
^
../macros.h:168:25: note: in expansion of macro '_BV'
#define CBI(n,b) (n &= ~_BV(b))
^~~
../MarlinSerial.cpp:367:19: note: in expansion of macro 'CBI'
if (h == t) CBI(M_UCSRxB, M_UDRIEx); // (Non-atomic, could be reenabled by the main program, but eventually this will succeed)
^~~
../MarlinSerial.cpp: At global scope:
../MarlinSerial.cpp:371:10: error: expected constructor, destructor, or type conversion before '(' token
ISR(M_USARTx_UDRE_vect) { _tx_udr_empty_irq(); }
^
../MarlinSerial.cpp: In static member function 'static void MarlinSerial::begin(long int)':
../MarlinSerial.cpp:384:14: warning: unused variable 'baud_setting' [-Wunused-variable]
uint16_t baud_setting;
^~~~~~~~~~~~
../MarlinSerial.cpp:385:10: warning: unused variable 'useU2X' [-Wunused-variable]
bool useU2X = true;
^~~~~~
../MarlinSerial.cpp: In static member function 'static void MarlinSerial::write(uint8_t)':
../MarlinSerial.cpp:519:18: error: lvalue required as left operand of assignment
M_UDRx = c;
^
In file included from ../MarlinConfig.h:27:0,
from ../MarlinSerial.cpp:36:
../macros.h:165:25: error: lvalue required as left operand of assignment
#define _BV(b) (1 << (b))
^
../macros.h:167:24: note: in expansion of macro '_BV'
#define SBI(n,b) (n |= _BV(b))
^~~
../MarlinSerial.cpp:524:9: note: in expansion of macro 'SBI'
SBI(M_UCSRxA, M_TXCx);
^~~
../macros.h:165:25: error: lvalue required as left operand of assignment
#define _BV(b) (1 << (b))
^
../macros.h:167:24: note: in expansion of macro '_BV'
#define SBI(n,b) (n |= _BV(b))
^~~
../MarlinSerial.cpp:553:7: note: in expansion of macro 'SBI'
SBI(M_UCSRxB, M_UDRIEx);
^~~
make: *** [MarlinSerial.o] Error 1