I was having difficulty generating this type of construct if (A) without using a Boolean type in which case there is no violation of rule 13.2.
Without a Boolean type, I get something along these lines:
if (A > 1) {
...}
I was using the R2015b release. It will be good if you can share an example model that generates this type of code.
Also, all the listed rules (10.1, 12.6, 13.2) are recommended and not obligatory as per the MISRA AC AGC standard (Guidelines for the application of MISRA-C: 2004 in the context of automatic code generation).
So compliance to those rules is dependent on the criticality of your application.
Even in the latest MISRA 2012 standard where these rules have been reclassified, they are still classified as advisory in the context of generated code.
For general information on MISRA compliance of generated code this is a great reference:
http://www.mathworks.com/solutions/automotive/standards/misra-c.html
or
http://www.mathworks.com/solutions/aerospace-defense/standards/misra-c.html