(toplevel patch) host subconfigures in Makefile, fixed version

[Nathanael Nerode]

>>  # gcc is the only module which uses GCC_FLAGS_TO_PASS.
>
>Could we use an automake conditional to cut down on the replication?
                     ^^^^s/make/gen

We certainly can, and will.  Bruce actually sent me a decent way of 
doing this.  The reason I wrote things out is that I 
actually anticipate some changes for purposes of accuracy, and I 
wouldn't be at all surprised if gcc's 'configure' section ought to 
deviate from that of other host modules.

In my previous completed versions, there's actually a section in 
Makefile.def called "flags_to_pass", with an entry for each flag,
and Makefile.tpl simply loops over them, inserting the ones appropriate
for the situation.  I intend to do that eventually.  (Which flags are 
passed down when is a great mish-mash right now and I want to spend some 
time simplifying it as much as I can.)

(My ideal layout involves adding a HOST_SUBDIR as well as BUILD_SUBDIR 
and TARGET_SUBDIR, and effectively unifying all of those sections.  
There's some evidence that this isn't a good idea though.)

>> +expect/Makefile: configure-tcl maybe-configure-tk
>
>No maybe here?

I believe that I tried it with TCL installed and not in the tree, and it 
failed.  It shouldn't have though... so you're right, that should be a 
maybe.  Will change.

--Nathanael