i had that same problem...
i think i fixed it by not installing it from the directory that newlib was in...i know it sounds retarded but i think it actually worked
ie : say newlib is in /some/dir/newlib-1.11.0
do :
`cd /some/dir` *** don't cd into the newlib-1.11.0 directory
`newlib-1.11.0/configure && make && make install`
i'm almost positive that's what i had to do...not sure exactly why. those files that it cries about are plain as day in that directory ....
hope it works for ya...the gba is a cool machine