* config.gcc (sparc64-*-solaris2*, sparcv9-*-solaris2*): Add
	tm-dwarf2.h to tm_file.
	(sparc-*-solaris2*): Add tm-dwarf2.h to tm_file for Solaris 7+.
	* config/sparc/sol2-bi.h (PREFERRED_DEBUGGING_TYPE): Delete.
	(ASM_DEBUG_SPEC): Delete.

Co-Authored-By: Rainer Orth <ro@TechFak.Uni-Bielefeld.DE>

From-SVN: r81428