dyn-string.h: New file.

dyn-string.h: New file.

	* dyn-string.h: New file.
	* dyn-string.c: Likewise.
	* Makefile.in (OBJS): Add dyn-string.o.
	(dwarf2out.o): Add dyn-string.h dependency.
	(dyn-string.o): List dependencies.
	* dwarf2out.c: Include dyn-string.h.
	(ASM_NAME_TO_STRING): Use dyn_string_append, rather than strcpy.
	(addr_const_to_string): Take a dyn_string_t, not a char* as a
	prototype.  Use dyn_string_append rather than strcat, throughout.
	(addr_to_string): Use dyn_string_t.

From-SVN: r21496