understand what it is trying to do, but I suspect it's not doing
it.
* config/ns32k/merlin.mh: Add comment about M_INSTALL.
* config/m88k/{delta88.mh,delta88v4.mh}: Remove M_INSTALL and
M_UNINSTALL; it tries to install a non-existent file gdb.z.
* Makefile.in: Remove M_INSTALL stuff; the above were the only uses.