* output.cc (Output_reloc<SHT_REL>::local_section_offset): Add

	* output.cc (Output_reloc<SHT_REL>::local_section_offset): Add
	addend parameter.  Change caller.  Handle merge sections.
	(Output_reloc<SHT_REL>::symbol_value): Change parameter type from
	Address to Addend.  Don't add in the result of
	local_section_offset, pass down the addend and use the returned
	value.
	* output.h (class Output_reloc<SHT_REL>): Add Addend typedef.
	Update declarations of local_section_offset and symbol_value.
	* testsuite/two_file_test_1.cc (t18): New function.
	* testsuite/two_file_test_2.cc (f18): New function.
	* testsuite/two_file_test_main.cc (main): Call t18.
	* testsuite/two_file_test.h (t18, f18): Declare.