Allows optimisation of cases like:
import micropython
_DEBUG = micropython.const(False)
if _DEBUG:
print('Debugging info')
Previously the 'if' statement was only optimised out if the type of the
const() argument was integer.
The change is implemented in a way that makes the compiler slightly smaller
(-16 bytes on PYBV11) but compilation will also be very slightly slower.
As a bonus, if const support is enabled then the compiler can now optimise
const truthy/falsey expressions of other types, like:
while "something":
pass
... unclear if that is useful, but perhaps it could be.
Signed-off-by: Angus Gratton <angus@redyak.com.au>
