make autogenerated functions to be 'static inline' instead of 'inline'

This fixes link issue and compile warning, for more details about this
issue look at
https://bitbucket.org/mjsousa/matiec/issues/53/c-compiler-warning-if-iec-function-is-used

STD_TEST.st
STD_RESSOURCE.c
LOCATED_VARIABLES.h
POUS.c
test
STD_CONF.c
SFC_TEST.st
test.exe
plc.st
POUS.h
VARIABLES.csv