Fix override keyword being print to the left side

Previously, the `override` keyword in C++ was being print in the left
side of a method decl, which is unsupported by C++ standard. This commit
fixes that by setting the `CanPrintOnLeft` field to 0, forcing it to be
print on the right side of the decl.

Signed-off-by: Giuliano Belinassi <gbelinassi@suse.de>