Rebuild trickiness with new module loading

[Edward Z. Yang]

I think a little care will need to be taken when rebuilding
projects after the new module loading code:

=====> rn.prog006(normal) 722 of 2717 [0, 0, 0]
cd ./rename/prog006 && $MAKE -s --no-print-directory rn.prog006    </dev/null >rn.prog006.run.stdout 2>rn.prog006.run.stderr
Wrong exit code (expected 0 , actual 2 )
Stdout:

Stderr:
pwd.o:(.text+0x19): undefined reference to `__stginit_directoryzm1zi1zi0zi0_SystemziDirectory_'
pwd.o:(.text+0x20): undefined reference to `__stginit_base_SystemziEnvironment_'
pwd.o:(.text+0x27): undefined reference to `__stginit_base_Prelude_'
pwd.o:(.text+0x2e): undefined reference to `__stginit_base_GHCziTopHandler_'
collect2: ld returned 1 exit status
make[2]: *** [rn.prog006] Error 1

Cleaning out the files made the error go away, but it's some food for thought.
Maybe we can do something to help things out?  Or perhaps the Makefile is
just confused.

Cheers,
Edward