When creating object files during testing, base the name of the object
file on the name of the source file, rather than using dump0.o,
dump1.o, etc. There's a few places where we have multiple source
files with the same name but in different directories, in these cases,
even after this change, we still add a numerical suffix to make the
object file names unique. So if we have 'foo/src.s' and 'bar/src.s',
we will create object files 'src.o' and 'src1.o'.
Update the few tests that hard code the object file name into the
expected test results.
ld/ChangeLog:
* testsuite/lib/ld-lib.exp (run_dump_test): Use object file names
based on the original source file name.
* testsuite/ld-discard/extern.d: Update object file names.
* testsuite/ld-discard/start.d: Likewise.
* testsuite/ld-discard/static.d: Likewise.
* testsuite/ld-elf/orphan-8.map: Likewise.