CheckBufferOverrun: Use portability warning for pointer arithmetic UB. It can be used by intention and usually works as intended.
checkUnreachableCode(): fix FP for statements that just hide compiler warnings about unused function arguments

Seen throughout the rockbox codebase.
pep8 fix

pep8 reported:
extracttests.py:233:16: E713 test for membership should be 'not in'
CheckBufferOverrun: Added comment in code to clarify why severity is portability for pointerOutOfBounds message.
python3 compatibility
Fixed #6350 (Tokenizer::simplifyCast: set Token::isCasted when cast is removed)
Incomplete statement: tweaked bailout for '(void*)0' using isCasted()
Renamed isCasted to isCast
Token: Added flag for attribute noreturn (#6328)
Refactoring Tokenizer::simplifyAttribute
Merge branch 'master' into travis_gcc_testsuite