[wscript] More fixes for -Wl,--as-needed

Reportedly, f28523ff54 was incomplete.

dbus/wscript

@@ -67,7 +67,7 @@ def build(bld):
         ]
     obj.use = ['serverlib']
     if bld.env['IS_LINUX']:
-        obj.use += ['PTHREAD', 'DL', 'RT', 'DBUS-1', 'EXPAT']
+        obj.use += ['PTHREAD', 'DL', 'RT', 'DBUS-1', 'EXPAT', 'STDC++']
     if bld.env['IS_MACOSX']:
         obj.use += ['PTHREAD', 'DL', 'DBUS-1', 'EXPAT']
     obj.target = 'jackdbus'

example-clients/wscript

@@ -137,14 +137,14 @@ def build(bld):
         prog.includes = os_incdir + ['../common/jack', '../common']
         prog.source = ['alsa_in.c', '../common/memops.c']
         prog.env.append_value("CFLAGS", "-DNO_JACK_ERROR")
-        prog.use = ['clientlib', 'ALSA', 'SAMPLERATE']
+        prog.use = ['clientlib', 'ALSA', 'SAMPLERATE', 'M']
         prog.target = 'alsa_in'
 
         prog = bld(features = 'c cprogram')
         prog.includes = os_incdir + ['../common/jack', '../common']
         prog.source = ['alsa_out.c', '../common/memops.c']
         prog.env.append_value("CFLAGS", "-DNO_JACK_ERROR")
-        prog.use = ['clientlib', 'ALSA', 'SAMPLERATE']
+        prog.use = ['clientlib', 'ALSA', 'SAMPLERATE', 'M']
         prog.target = 'alsa_out'
 
     for example_lib, example_lib_source in list(example_libs.items()):