Only a handful of ISO 639-3 languages are supported by Qt. Standard Malay is not one of them. Using the macrolanguage code seems fine. Not too sure what the numerusform is for a macrolanguage, but appears that wikipedia equates MS w/ "bahasa" too
As a special exception, FreeType can also be built with the 'makepp'
build tool, available from http://makepp.sourceforge.net.
Note, however. that you will need at least version 1.19 and pass the
option --norc-substitution to have it work correctly.