Pass -B to objcopy binary symbol test

[Maciej W. Rozycki]

On Fri, 31 Oct 2025, Alan Modra wrote:

> objcopy -I binary -O some_coff_target does not currently work without
> choosing a valid arch with -B.  This used to be the case for ELF
> targets too, until commit 6765ee1825d9.

 FWIW this test still fails for numerous targets:

aarch64-darwin  +FAIL: binary symbol (implicit)
aarch64-darwin  +FAIL: binary symbol (explicit)
arm-darwin  +FAIL: binary symbol (implicit)
arm-darwin  +FAIL: binary symbol (explicit)
hppa-hp-hpux10  +FAIL: binary symbol (implicit)
hppa-hp-hpux10  +FAIL: binary symbol (explicit)
i386-darwin  +FAIL: binary symbol (implicit)
i386-darwin  +FAIL: binary symbol (explicit)
kvx-elf  +FAIL: binary symbol (implicit)
kvx-elf  +FAIL: binary symbol (explicit)
kvx-linux  +FAIL: binary symbol (implicit)
kvx-linux  +FAIL: binary symbol (explicit)
powerpc-darwin  +FAIL: binary symbol (implicit)
powerpc-darwin  +FAIL: binary symbol (explicit)
x86_64-darwin  +FAIL: binary symbol (implicit)
x86_64-darwin  +FAIL: binary symbol (explicit)

Wasn't it possible to wire using standard `run_dump_test' infrastructure 
rather than coming up with this ad-hoc TCL code?  It would have helped 
with diagnostics, output such as:

                 U _binary__scratch_vol1_binutils_binutils_test_binutils_src_binutils_testsuite_binutils_all_version_s_end
                 U _binary__scratch_vol1_binutils_binutils_test_binutils_src_binutils_testsuite_binutils_all_version_s_size
                 U _binary__scratch_vol1_binutils_binutils_test_binutils_src_binutils_testsuite_binutils_all_version_s_start
                 U _binary__scratch_vol1_binutils_binutils_test_binutils_src_binutils_testsuite_binutils_all_version_s_end
                 U _binary__scratch_vol1_binutils_binutils_test_binutils_src_binutils_testsuite_binutils_all_version_s_size
                 U _binary__scratch_vol1_binutils_binutils_test_binutils_src_binutils_testsuite_binutils_all_version_s_start

expected: _binary__scratch_vol1_binutils_binutils_test_binutils_src_binutils_testsuite_binutils_all_version_s_end _binary__scratch_vol1_binutils_binutils_test_binutils_src_binutils_testsuite_binutils_all_version_s_size _binary__scratch_vol1_binutils_binutils_test_binutils_src_binutils_testsuite_binutils_all_version_s_start, actual: 
FAIL: binary symbol (implicit)

surely does not indicate what's wrong (taken from `aarch64-darwin' in this 
case).

  Maciej