Fix compile with sanitize address & undefined

On Debian 9, the sanitize library exports only dlopen symbol, but
it doesn't export the other ones.
We need to check all dl symbols that we use, otherwise "-ldl" will
not be added to the libs list.

Task-number: QTBUG-64864
Change-Id: I3e62b82985348c40b8b61302ba589d5564598e18
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>

src/corelib/configure.json

@@ -130,7 +130,11 @@
             "label": "dlopen()",
             "test": {
                 "include": "dlfcn.h",
-                "main": "dlopen(0, 0);"
+                "main": [
+                    "dlclose(dlopen(0, 0));",
+                    "dlsym(RTLD_DEFAULT, 0);",
+                    "dlerror();"
+                ]
             },
             "sources": [
                 "",