testsuite: Update pr94426-2 test to handle more targets [PR94426]

The function (_Z4InitIN3VARIZ1qvEUlvE_EUlvE_EEbT_) that initializes
VAR has changed siganture.  It was was weak / comdat [Linux] or
weak / global [Darwin] and now is text section local.

So: test that the symbol exists, is spelled the way intended by the
ABI mangling and is not weak (or global on Darwin).

gcc/testsuite/ChangeLog:

2020-04-16  Iain Sandoe  <iain@sandoe.co.uk>

	PR c++/94426
	* g++.dg/cpp0x/lambda/pr94426-2.C: Adjust scan-asms to test
	for the change on more platforms.