gold: Remove NaCl target support

gold: Remove NaCl target support

NaCl has been deprecated:

https://developer.chrome.com/docs/native-client/migration/

It is now in the process of being removed from llvm:

https://github.com/llvm/llvm-project/pull/133661

Remove NaCl target support from gold.

	* Makefile.am (CCFILES): Remove nacl.cc.
	(HFILES): Remove nacl.h.
	* Makefile.in: Regenerated.
	* aarch64.cc: Don't include nacl.h.
	* arm.cc: Don't include nacl.h.
	(Target_arm_nacl): Removed.
	(Output_data_plt_arm_nacl): Likewise.
	(target_selector_arm): Replace Target_arm_nacl with
	Target_selector_arm.
	* i386.cc: Don't include nacl.h.
	(Output_data_plt_i386_nacl): Removed.
	(Target_i386_nacl): Likewise.
	(target_selector_i386): Replace Target_selector_i386_nacl with
	Target_selector_i386.
	* mips.cc: Don't include nacl.h.
	(Target_mips_nacl): Removed.
	(Target_selector_mips_nacl): Likewise.
	(target_selector_mips32): Replace Target_selector_mips_nacl with
	Target_selector_mips.
	(target_selector_mips32el): Likewise.
	(target_selector_mips64): Likewise.
	(target_selector_mips64el): Likewise.
	* nacl.cc: Removed.
	* nacl.h: Likewise.
	* x86_64.cc: Don't include nacl.h.
	(Output_data_plt_x86_64_nacl): Removed.
	(Target_x86_64_nacl): Likewise.
	(target_selector_x86_64): Replace Target_x86_64_nacl with
	Target_selector_x86_64.
	(target_selector_x32): Likewise.
	* po/POTFILES.in: Regenerated.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>