[Ada] Propagate load addresses for traceback cache on Linux

[Ada] Propagate load addresses for traceback cache on Linux

Symbolization of traceback addresses through shared libraries
requires information on the shared libraries load addresses, which
was at hand on Linuxbut not propagated through the runtime when
caching is enabled.  This change fixes this.

2018-05-21  Olivier Hainque  <hainque@adacore.com>

gcc/ada/

	* libgnat/s-trasym__dwarf.adb (Add_Module_To_Cache): Expect a
	Load_Address argument and pass it down to Init_Module.
	* libgnat/s-tsmona__linux.adb (Build_Cache_For_All_Modules): Pass
	lm.l_addr as the Load_Address to Add_Module_To_Cache.

From-SVN: r260448