utils/lstopo: don't build lstopo-win with MSVC

Clang can be used in "MSVC mode" to build hwloc using autotools.
That mode doesn't support -mwindows just like MSVC doesn't.
-mwindows is the only difference between lstopo-win and lstopo,
so just disable lstopo-win instead of building both identically.

Closes #631

Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>

utils/lstopo/Makefile.am

@@ -52,18 +52,19 @@ lstopo_CFLAGS = $(lstopo_no_graphics_CFLAGS) $(HWLOC_CAIRO_CFLAGS)
 lstopo_LDADD += $(HWLOC_CAIRO_LIBS) $(HWLOC_X11_LIBS)
 endif
 if HWLOC_HAVE_WINDOWS
-bin_PROGRAMS += lstopo lstopo-win
+bin_PROGRAMS += lstopo
+if !HWLOC_HAVE_MSVC
+# only build lstopo-win if NOT building with MSVC (or Clang in MSVC mode) because it doesn't support -mwindows
+bin_PROGRAMS += lstopo-win
+endif
 lstopo_SOURCES += lstopo-windows.c
 lstopo_CPPFLAGS += -DLSTOPO_HAVE_GRAPHICS
 if HWLOC_HAVE_USER32
 lstopo_LDADD += -luser32
 endif
 lstopo_win_SOURCES = $(lstopo_SOURCES)
 lstopo_win_CPPFLAGS = $(lstopo_CPPFLAGS)
-lstopo_win_CFLAGS = $(lstopo_CFLAGS)
-if !HWLOC_HAVE_MSVC
-lstopo_win_CFLAGS += -mwindows
-endif
+lstopo_win_CFLAGS = $(lstopo_CFLAGS) += -mwindows
 lstopo_win_LDADD = $(lstopo_LDADD)
 endif