"make world" to fail if you use the msun math library and
blow away /usr/include and then do "make world". This is because
the msun math.h isn't installed with the other include files before
xlint is built. It finally gets installed when the msun library
is built.
Perhaps "make world" should install the msun math.h file if
it doesn't install the CSRG math.h, to prevent problems
like this in the future.
778413c81b