* dwarf_reader.cc (Sized_dwarf_line_info): Include all lines,

	* dwarf_reader.cc (Sized_dwarf_line_info): Include all lines,
	but mark earlier ones as non-canonical
	(offset_to_iterator): Update search target and example
	(do_addr2line): Return extra lines in a vector*
	(format_file_lineno): Extract from do_addr2line
	(one_addr2line): Add vector* out-param
	* dwarf_reader.h (Offset_to_lineno_entry): New field recording
	when a lineno entry appeared last for its instruction
	(Dwarf_line_info): Add vector* out-param
	* object.cc (Relocate_info): Pass NULL for the vector* out-param
	* symtab.cc (Odr_violation_compare): Include the lineno in the
	comparison again.
	(linenos_from_loc): New. Combine the canonical line for an
	address with its other lines.
	(True_if_intersect): New. Helper functor to make
	std::set_intersection a query.
	(detect_odr_violations): Compare sets of lines instead of just
	one line for each function. This became less deterministic, but
	has fewer false positives.
	* symtab.h: Declarations.
	* testsuite/Makefile.am (odr_violation2.o): Compile with -O2 to
	mix an optimized and non-optimized object in the same binary
	(odr_violation2.so): Same.
	* testsuite/Makefile.in: Regenerate from Makefile.am.
	* testsuite/debug_msg.cc (main): Make OdrDerived classes.
	* testsuite/debug_msg.sh: Update line numbers and add
	assertions.
	* testsuite/odr_violation1.cc: Use OdrDerived, in a
	non-optimized context.
	* testsuite/odr_violation2.cc: Make sure Ordering::operator()
	isn't inlined, and use OdrDerived in an optimized context.
	* testsuite/odr_header1.h: Defines OdrDerived, where
	optimization will change the
	first-instruction-in-the-destructor's file and line number.
	* testsuite/odr_header2.h: Defines OdrBase.