Only build both Wine binaries on Linux, pthread support doesn't work
on other platforms.

diff --git a/configure.ac b/configure.ac
index 1a7dd69..75b29bd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -36,12 +36,6 @@
 then
     AC_DEFINE(NO_TRACE_MSGS,1,[Define to disable trace messages.])
 fi
-if test "x$with_nptl" = "xyes"
-then
-    AC_SUBST(MAIN_BINARY,"wine-pthread")
-else
-    AC_SUBST(MAIN_BINARY,"wine-kthread")
-fi
 
 dnl **** Check for some programs ****
 
@@ -918,10 +912,25 @@
 esac
 
 dnl Mingw needs explicit msvcrt for linking libwine
-AC_SUBST(CRTLIBS,"")
 case $host_os in
   mingw32*)
-    CRTLIBS="-lmsvcrt" ;;
+    AC_SUBST(CRTLIBS,"-lmsvcrt") ;;
+esac
+
+case $host_os in
+  linux*)
+    AC_SUBST(WINE_BINARIES,"wine-kthread wine-pthread")
+    if test "x$with_nptl" = "xyes"
+    then
+        AC_SUBST(MAIN_BINARY,"wine-pthread")
+    else
+        AC_SUBST(MAIN_BINARY,"wine-kthread")
+    fi
+    ;;
+  *)
+    AC_SUBST(WINE_BINARIES,"wine-kthread")
+    AC_SUBST(MAIN_BINARY,"wine-kthread")
+    ;;
 esac
 
 dnl **** Get the soname for libraries that we load dynamically ****