Add R_X86_64_PC32_BND/R_X86_64_PLT32_BND suppor to gold

Add R_X86_64_PC32_BND/R_X86_64_PLT32_BND suppor to gold

elfcpp/

	* x86_64.h (R_X86_64_PC32_BND): New.
	(R_X86_64_PLT32_BND): Likewise.

gold/

	* x86_64.cc (Target_x86_64<size>::Scan::get_reference_flags):
	Handle R_X86_64_PC32_BND and R_X86_64_PLT32_BND just like
	R_X86_64_PC32 and R_X86_64_PLT32, respectively.
	(Target_x86_64<size>::Scan::local): Likewise.
	(Target_x86_64<size>::Scan::global): Likewise.
	(Target_x86_64<size>::Relocate::relocate): Likewise.
	(Target_x86_64<size>::Relocatable_size_for_reloc::get_size_for_reloc):
	Likewise.
	(Target_x86_64<size>::Scan::check_non_pic(): Handle
	R_X86_64_PC32_BND.

	* testsuite/Makefile.am (check_PROGRAMS): Add
	exception_x86_64_bnd_test.
	(exception_x86_64_bnd_test_SOURCES): New macro.
	(exception_x86_64_bnd_test_DEPENDENCIES): Likewise.
	(exception_x86_64_bnd_test_LDFLAGS): Likewise.
	(exception_x86_64_bnd_test_LDADD): Likewise.
	(exception_x86_64_bnd_1.o): New rule.
	(exception_x86_64_bnd_2.o): Likewise.
	* testsuite/Makefile.in: Regenerated.