Riscv ld-elf/stab failure and fake label cleanup.

Riscv ld-elf/stab failure and fake label cleanup.

	* as.c: Include write.h.
	(common_emul_init): Use FAKE_LABEL_NAME.
	* ecoff.c (add_file, ecoff_directive_end, ecoff_directive_loc):
	Likewise.
	(ecoff_build_symbols): Use FAKE_LABEL_CHAR.
	* expr.c (get_symbol_name): Use FAKE_LABEL_CHAR.  Accept only if
	input_from_string is TRUE.
	* read.c (input_from_string): New.
	(read_symbol_name): Use FAKE_LABEL_CHAR.  Accept only if
	input_from_string is TRUE.
	(temp_ilp): Set input_from_string to TRUE.
	(restore_ilp): Set input_from_string to FALSE.
	* read.h (input_from_string): Declare.
	* symbols.c: Include write.h
	(S_IS_LOCAL): Check for FAKE_LABEL_CHAR.
	(symbol_relc_make_sym): Fix comment refering to default fake label
	string.
	* write.h (FAKE_LABEL_CHAR): New.
	* config/tc-riscv.h (FAKE_LABEL_CHAR): Define.
	* testsuite/gas/all/err-fakelabel.s: New.