vxworks.h (VXWORKS_LIB_SPEC): Incorporate ...

vxworks.h (VXWORKS_LIB_SPEC): Incorporate ...

2017-06-27  Jerome Lambourg  <lambourg@adacore.com>
            Olivier Hainque  <hainque@adacore.com>

	* config/vxworks.h (VXWORKS_LIB_SPEC): Incorporate ...
	(TLS_SYM): New local macro, forcing reference to __tls__ on
	link command lines for VxWorks 7 RTPs, triggering initialization
	of tlsLib.
	(VXWORKS_HAVE_TLS): New macro. State whether the target VxWorks
	OS features TLS support, true for RTPs on VxWorks 7.
	* config/vxworks.c (vxworks_override_options): Setup emutls
	accordingly.

Co-Authored-By: Olivier Hainque <hainque@adacore.com>
From-SVN: r249684