Do not use -Bsymbolic* on anything but x86 and x86-64

We're getting problems with PMF comparisons failing on ARM and PPC,
which in turn break the new PMF-based connect syntax.
Dropping -Bsymbolic* seems to work around the issue (which has
been reported upstream, and it's likely to be a linker issue,
see the discussion in the bug report).

Task-number: QTBUG-36129
Change-Id: I8675a57acf26fdb9fbbc4d03896d5f6a9a96d506
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

config.tests/unix/bsymbolic_functions.test

@@ -6,6 +6,10 @@ VERBOSE=$2
 
 
 cat >>bsymbolic_functions.c << EOF
+#if !(defined(__i386) || defined(__i386__) || defined(__x86_64) || defined(__x86_64__) || defined(__amd64))
+#error "Symbolic function binding on this architecture may be broken, disabling it (see QTBUG-36129)."
+#endif
+
 int main() { return 0; }
 EOF