test: Use libXext.so.0 instead of libXext.so.6 on Solaris

Reviewed-by: Aaron Plattner <aplattner@nvidia.com>

test/dlclose.c

@@ -28,13 +28,19 @@ static int countOpenFDs(void)
     return count;
 }
 
+#if defined(__sun)
+static const char libXext_so[] = "libXext.so.0";
+#else
+static const char libXext_so[] = "libXext.so.6";
+#endif
+
 int main(void)
 {
     // Work around a bug in libXext: dlclosing it after it has registered the
     // Generic Event Extension causes an identical bug to the one this program
     // is trying to test for.
     int nOpenFDs = countOpenFDs();
-    void *libXext = dlopen("libXext.so.6", RTLD_LAZY);
+    void *libXext = dlopen(libXext_so, RTLD_LAZY);
     void *libvdpau = dlopen("src/libvdpau.so", RTLD_LAZY);
     Display *dpy = XOpenDisplay(NULL);
     VdpDeviceCreateX11 *pvdp_device_create_x11;
@@ -43,7 +49,7 @@ int main(void)
     VdpStatus status;
 
     if (!libXext) {
-        fprintf(stderr, "Failed to open libXext.so.6: %s", dlerror());
+        fprintf(stderr, "Failed to open %s: %s", libXext_so, dlerror());
         return SKIP;
     }