Remove TYPE_NOSIGN "char" hack

Remove TYPE_NOSIGN "char" hack

init_type (and arch_integer_type) currently use a special hack to set the
TYPE_NOSIGN flag if the type name is exactly "char".  This commit moves the
hack up to the callers of those routines.

The special case currently can hit only for types created from dwarf2read,
but read_base_type actually implements the "char" check itself, so it is
redundant to do it in init_type as well.  (Note that stabsread.c and the
other type readers always pass NULL as name to init_type, so the special
case can never hit for those.)

A few other cases create pre-definded types with a hard-coded name of "char";
the commit simply moves setting the TYPE_NOSIGN flag to those places.

No functional change intended.

gdb/ChangeLog:

	* gdbtypes.c (init_type): Remove "char" special case.
	(arch_integer_type): Likewise.
	(gdbtypes_post_init): Set TYPE_NOSIGN for "char" type.
	(objfile_type): Likewise.
	* mdebugread.c (basic_type): Likewise.
	* stabsread.c (rs6000_builtin_type): Likewise.

Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>