re PR middle-end/45862 (SUPPORTS_WEAK is documented as a C expression, used as a compile time constant)

	PR middle-end/45862
	* doc/tm.texi.in (SUPPORTS_WEAK): Update.
	(TARGET_SUPPORTS_WEAK): New.
	* doc/tm.texi: Regenerate.
	* defaults.h (SUPPORTS_WEAK): Update comment.
	(TARGET_SUPPORTS_WEAK): New.
	* dwarf2asm.c (USE_LINKONCE_INDIRECT): Update define.
	* varasm.c (assemble_external): Use TARGET_SUPPORTS_WEAK instead of
	SUPPORTS_WEAK.
	(merge_weak, declare_weak, do_assemble_alias, supports_one_only,
	make_decl_one_only): Likewise.
	* config/pa/som.h (SUPPORTS_WEAK): Rename defines to
	TARGET_SUPPORTS_WEAK.
	(SUPPORTS_ONE_ONLY, MAKE_DECL_ONE_ONLY): Use TARGET_SUPPORTS_WEAK
	instead of SUPPORTS_WEAK.

From-SVN: r165319