In case there also was a Shrs(x, 31),
CSE can be applied after instruction selection.

ia32: Simply make the fpcw caller (and callee) saved, so we do not need a special case when generating a call.

'mov $~0x80000000, %r; ror x, %r' is shorter than 'mov $0x80000000, %r; shr x, %r; not %r'.

'Or' cannot have float mode.

'mov $~1, %r; rol x, %r' is shorter than 'mov $1, %r; shl x, %r; not %r'.

At least __builtin_return_address(0) with -fomit-frame-pointer works
again (the variant with frame pointer is still broken).

This fixes backend/destam_flags3.c.

This fixes backend/duplicate_proj.c.

This fixes multiple tests with -O0.

This is done by introducing a new new_global_entity() function for
constructing globals/adding a visibility argument to new_alias_entity().

This fixes opt/fehler311.c.

We can get a proper mode for pointer-pointer from
get_reference_offset_mode().

This flag can be set on entities where the actual address isn't
known/compared against other address. This also fixes a bug where we
used the mach-o csrings section for global char arrays which need
distinct addresses.

tarval_convert_to() does not return tv_unknown or null pointer.

Just use the code present in the Cmp/Sub-optimization to see if it will
trigger.

This fixes opt/fehler304.c

This resolves problems with hidden dependencies during code selection, which cause dependency cycles and therefore fixes backend/scheduled.c.
Also it grants the code selection slightly more freedom by not arbitrarily restricting the order by stack dependencies.

be: Pass the input requirements directly to the constructors of nodes, which have a variable number of arguments.

Thanks to Christoph for the code review.

This fixes backend/destam_flags2.c.

This fixes opt/fehler285.c.

This is the first half for properly supporting switch in PIC.
The entries of the table need to be adapted to PIC, too.