Global patches that affect various configurations in various ways tend to
break configurations.  People usually make an effort with global search and
replace, but all too often some details are overlooked (or simply mistyped).

This Makefile is supposed to give coverage of all the main configure targets
and notable variants that enable different config files.
Each target is configured, using --enable-werror-always, and then we attempt
to build 'all-gcc'.  configuration and make output is collected in a 'log'
directory.
This is based on config-list.mk in the pr46489-20101227-branch, but with
configurations removed that have been recently removed or obsoleted.
This leaves 193 configurations, of which 23 currently appear to be broken
(according to a test run on gcc20).  These are:

alpha-dec-osf5.1
am33_2.0-linux
arm-freebsd6
arm-wince-pe
avr-elf
avr-rtems
i586-netware --with-ld=../scripts/nwld
i686-openbsd3.0
i686-pc-msdosdjgpp
i686-wrs-vxworksae
iq2000-elf
lm32-elf
lm32-rtems
lm32-uclinux
m68k-openbsd
microblaze-elf
microblaze-linux
mips-openbsd
mn10300-elf
powerpc-wrs-vxworksae
rs6000-ibm-aix5.2.0
rs6000-ibm-aix5.3.0
rs6000-ibm-aix6.0