* read.h : ditto.
* read.c (read_a_source_file): if no file when inst is read, set
generate_asm_lineno to true.
* ecoff.h : change name to generate_asm_lineno and add function
ecoff_no_current_file.
* ecoff.c : change name to generate_asm_lineno.
* ecoff.c (ecoff_generate_asm_lineno) : new function, to generate
ecoff style line for asm file.