Add -mevexrcig={rne|rd|ru|rz} option to x86 assembler.
It is used to control which value is encoded in rounding control bits
for SAE-only EVEX instructions.
gas/
* config/tc-i386.c (evexrcig): New.
(build_evex_prefix): Force rounding bits.
(OPTION_MEVEXRCIG): New.
(md_longopts): Add mevexrcig.
(md_parse_option): Handle OPTION_MEVEXRCIG.
(md_show_usage): Document mevexrcig.
* doc/c-i386.texi (mevexrcig): Document new option.
gas/testsuite/
* gas/i386/avx512dq-rcig.s: New.
* gas/i386/avx512dq-rcigrd-intel.d: Likewise.
* gas/i386/avx512dq-rcigrd.d: Likewise.
* gas/i386/avx512dq-rcigrne-intel.d: Likewise.
* gas/i386/avx512dq-rcigrne.d: Likewise.
* gas/i386/avx512dq-rcigru-intel.d: Likewise.
* gas/i386/avx512dq-rcigru.d: Likewise.
* gas/i386/avx512dq-rcigrz-intel.d: Likewise.
* gas/i386/avx512dq-rcigrz.d: Likewise.
* gas/i386/avx512er-rcig.s: Likewise.
* gas/i386/avx512er-rcigrd-intel.d: Likewise.
* gas/i386/avx512er-rcigrd.d: Likewise.
* gas/i386/avx512er-rcigrne-intel.d: Likewise.
* gas/i386/avx512er-rcigrne.d: Likewise.
* gas/i386/avx512er-rcigru-intel.d: Likewise.
* gas/i386/avx512er-rcigru.d: Likewise.
* gas/i386/avx512er-rcigrz-intel.d: Likewise.
* gas/i386/avx512er-rcigrz.d: Likewise.
* gas/i386/avx512f-rcig.s: Likewise.
* gas/i386/avx512f-rcigrd-intel.d: Likewise.
* gas/i386/avx512f-rcigrd.d: Likewise.
* gas/i386/avx512f-rcigrne-intel.d: Likewise.
* gas/i386/avx512f-rcigrne.d: Likewise.
* gas/i386/avx512f-rcigru-intel.d: Likewise.
* gas/i386/avx512f-rcigru.d: Likewise.
* gas/i386/avx512f-rcigrz-intel.d: Likewise.
* gas/i386/avx512f-rcigrz.d: Likewise.
* gas/i386/x86-64-avx512dq-rcig.s: Likewise.
* gas/i386/x86-64-avx512dq-rcigrd-intel.d: Likewise.
* gas/i386/x86-64-avx512dq-rcigrd.d: Likewise.
* gas/i386/x86-64-avx512dq-rcigrne-intel.d: Likewise.
* gas/i386/x86-64-avx512dq-rcigrne.d: Likewise.
* gas/i386/x86-64-avx512dq-rcigru-intel.d: Likewise.
* gas/i386/x86-64-avx512dq-rcigru.d: Likewise.
* gas/i386/x86-64-avx512dq-rcigrz-intel.d: Likewise.
* gas/i386/x86-64-avx512dq-rcigrz.d: Likewise.
* gas/i386/x86-64-avx512er-rcig.s: Likewise.
* gas/i386/x86-64-avx512er-rcigrd-intel.d: Likewise.
* gas/i386/x86-64-avx512er-rcigrd.d: Likewise.
* gas/i386/x86-64-avx512er-rcigrne-intel.d: Likewise.
* gas/i386/x86-64-avx512er-rcigrne.d: Likewise.
* gas/i386/x86-64-avx512er-rcigru-intel.d: Likewise.
* gas/i386/x86-64-avx512er-rcigru.d: Likewise.
* gas/i386/x86-64-avx512er-rcigrz-intel.d: Likewise.
* gas/i386/x86-64-avx512er-rcigrz.d: Likewise.
* gas/i386/x86-64-avx512f-rcig.s: Likewise.
* gas/i386/x86-64-avx512f-rcigrd-intel.d: Likewise.
* gas/i386/x86-64-avx512f-rcigrd.d: Likewise.
* gas/i386/x86-64-avx512f-rcigrne-intel.d: Likewise.
* gas/i386/x86-64-avx512f-rcigrne.d: Likewise.
* gas/i386/x86-64-avx512f-rcigru-intel.d: Likewise.
* gas/i386/x86-64-avx512f-rcigru.d: Likewise.
* gas/i386/x86-64-avx512f-rcigrz-intel.d: Likewise.
* gas/i386/x86-64-avx512f-rcigrz.d: Likewise.
* gas/i386/i386.exp: Run new tests.