A good way to set sub-target switch

[Doug Kwan (關振德)]

Hi,

    I am building a toolchain which is based on the arm-eabi target
but with a C library that requires the -mandroid switch.  I am having
problems building libstdc++-v3 and friends because the -mandroid is
being dropped left and right.  I tried exporting CFLAGS="-g -O2
-mandroid" in environment and forcing it in the make command line but
I still got errors because xgcc gets invoked without -mandroid
somewhere along the build.  Is there a good way to set mandatory flags
like this?

Thanks.

-Doug