Your libstdc++ testsuite changes causes regressions

[Hans-Peter Nilsson <hans-peter dot nilsson at axis dot com>]

Target cris-axis-elf, but you should see this for any newlib
target and likely others.  Worked with 124057, fails with 124060
(there are other fails, this is the regression):

Running /tmp/hpautotest-gcc1/gcc/libstdc++-v3/testsuite/libstdc++-dg/conformance.exp ...
...
FAIL: abi/cxx_runtime_only_linkage.cc (test for excess errors)
FAIL: abi/header_cxxabi.c (test for excess errors)

Apparently your change causes one of the "-B/..." options to be
truncated to "B/".  I don't see exactly what in your patch that
causes this, sorry.

The new 124060 libstdc++.log says:
...
extra_tool_flags are:
 -x c -lsupc++
compiling and executing as C, not C++
Executing on host: /tmp/hpautotest-gcc1/cris-elf/gccobj/./gcc/xgcc -B/tmp/hpautotest-gcc1/cris-elf/gccobj/./gcc/ B/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/newlib/ -isystem /tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/newlib/targ-include -isystem /tmp/hpautotest-gcc1/gcc/newlib/libc/include -B/tmp/hpautotest-gcc1/cris-elf/pre/cris-elf/bin/ -B/tmp/hpautotest-gcc1/cris-elf/pre/cris-elf/lib/ -isystem /tmp/hpautotest-gcc1/cris-elf/pre/cris-elf/include -isystem /tmp/hpautotest-gcc1/cris-elf/pre/cris-elf/sys-include -B/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./libgloss/cris/ -L/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./libgloss/cris -L/tmp/hpautotest-gcc1/gcc/libgloss/cris  -I/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/libstdc++-v3/include/cris-elf -I/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/libstdc++-v3/include -I/tmp/hpautotest-gcc1/gcc/libstdc++-v3/libsupc++ -I/tmp/hpautotest-gcc1/gcc/libstdc++-v3/include/backward -I/tmp/hpautotest-gcc1/gcc/libstdc++-v3/tes!
 tsuite/util -L/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./libstdc++-v3/libsupc++/.libs /tmp/hpautotest-gcc1/gcc/libstdc++-v3/testsuite/abi/cxx_runtime_only_linkage.cc    -lsupc++   -isystem /tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./newlib/targ-include -isystem /tmp/hpautotest-gcc1/gcc/newlib/libc/include -B/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./libgloss/cris/ -L/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./libgloss/cris -L/tmp/hpautotest-gcc1/gcc/libgloss/cris  -B/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./newlib/ -L/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./newlib -sim3  -lm   -o ./cxx_runtime_only_linkage.exe    (timeout = 600)
xgcc: B/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/newlib/: No such file or directory
compiler exited with status 1
output is:
xgcc: B/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/newlib/: No such file or directory

FAIL: abi/cxx_runtime_only_linkage.cc (test for excess errors)
Excess errors:
xgcc: B/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/newlib/: No such file or directory
...

And the old 124057 .log says:
...
extra_tool_flags are:
 -x c -lsupc++
compiling and executing as C, not C++
Executing on host: /tmp/hpautotest-gcc1/cris-elf/gccobj/gcc/xgcc -B/tmp/hpautotest-gcc1/cris-elf/gccobj/gcc/ -B/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./libgloss/cris/ -L/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./libgloss/cris -L/tmp/hpautotest-gcc1/gcc/libgloss/cris  -I/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/libstdc++-v3/include/cris-elf -I/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/libstdc++-v3/include -I/tmp/hpautotest-gcc1/gcc/libstdc++-v3/libsupc++ -I/tmp/hpautotest-gcc1/gcc/libstdc++-v3/include/backward -I/tmp/hpautotest-gcc1/gcc/libstdc++-v3/testsuite/util -L/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./libstdc++-v3/libsupc++/.libs /tmp/hpautotest-gcc1/gcc/libstdc++-v3/testsuite/abi/cxx_runtime_only_linkage.cc    -lsupc++   -isystem /tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./newlib/targ-include -isystem /tmp/hpautotest-gcc1/gcc/newlib/libc/include -B/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./libgloss/cris/ -L/tmp/hpautotest-gcc1/cris-elf!
 /gccobj/cris-elf/./libgloss/cris -L/tmp/hpautotest-gcc1/gcc/libgloss/cris  -B/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./newlib/ -L/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./newlib -sim3  -lm   -o ./cxx_runtime_only_linkage.exe    (timeout = 600)
PASS: abi/cxx_runtime_only_linkage.cc (test for excess errors)
...

I may open a PR about this in a few days, if not resolved.

To repeat as above, a workaround for the current
autoconf/libtool issue with newlib targets is required, like
reverting the config-ml.in patch part in
<http://gcc.gnu.org/ml/gcc-patches/2007-04/msg00883.html>.

brgds, H-P