One more patch will be required, namely, to define OBJDUMP where
necessary. I've rolled these two patches together, as attached.
Explanation:
The AC_LIBTOOL_WIN32_DLL macro was supposed to be used in packages which
built on Win32 platforms, in order to create DLLs. This macro tested
for as, dlltool, and objdump. The latter is used in the file_magic test
to determine if a .a is a static or import library.
In 1.5 libtool worked anyway without it, because among other variables,
OBJDUMP was given a "sane default" near the beginning of libtool.m4 and
was always exported, and AS and DLLTOOL weren't needed.
so without the win32-dll arg to LT_INIT (or
the AC_LIBTOOL_WIN32_DLL compat macro), libtool refuses to link shared
libs against non-libtoolized shared libs, because the file_magic test on
the implib fails due to an undefined OBJDUMP variable. Assuring that
OBJDUMP is defined is therefore necessary for compatibility with
previous behaviour.
Not only that, but this may fix another possible bug on Linux ELF
systems, as there is a test on that platform (line 2461 after the patch)
which uses OBJDUMP, which I don't see where it would have been defined.