include: libsframe: rename SFrame V3 Flexible FDE macros to CTRLWORD

include: libsframe: rename SFrame V3 Flexible FDE macros to CTRLWORD

The existing SFrame V3 macros for Flexible FDEs used the term 'OFFSET'
to refer to the data word encoding control/register data word. This can
be confusing, as the control data word (register ID, dereference flags)
is distinct from a stack offset.

This patch renames these macros to use 'CTRLWORD' to better reflect
their purpose. It also updates the assembler and libsframe dumper to
use the new nomenclature.

No functional change.

Reviewed-by: Jens Remus <jremus@linux.ibm.com>
gas/
	* gen-sframe.c (sframe_get_fre_dataword_size): Use
	SFRAME_V3_FLEX_FDE_CTRLWORD_ENCODE.
	(output_sframe_row_entry_datawords): Likewise.
include/
	* sframe.h (SFRAME_V3_FLEX_FDE_REG_ENCODE): Rename from ..
	(SFRAME_V3_FLEX_FDE_CTRLWORD_ENCODE): .. to.
	(SFRAME_V3_FLEX_FDE_CTRLWORD_REGNUM): Rename from
	SFRAME_V3_FLEX_FDE_OFFSET_REG_NUM to this.
	(SFRAME_V3_FLEX_FDE_CTRLWORD_DEREF_P): Rename from
	SFRAME_V3_FLEX_FDE_OFFSET_REG_DEREF_P to this.
	(SFRAME_V3_FLEX_FDE_CTRLWORD_REG_P): Rename from
	SFRAME_V3_FLEX_FDE_OFFSET_REG_P to this.
	(SFRAME_V3_FRE_RA_UNDEFINED_P): Add new V3 macro.
libsframe/
	* sframe-dump.c (dump_sframe_func_fres_flex): Update all
	callers to use the new CTRLWORD macros.
libsframe/testsuite/
	* libsframe.decode/be-flipping-v3.c: Use renamed macros.