XCOREVBITMANIP builtins added

Files Changed:
gcc/common/config/riscv:
 * riscv-common.cc: Added the XCOREVBITMANIP extension.

gcc/config/riscv:
 * constraints.md: Added builtins for the XCOREVBITMANIP extension.
 * corev.def: Likewise.
 * corev.md: Likewise.
 * predicates.md: Likewise.
 * riscv-builtins.cc: Likewise.
 * riscv-ftypes.def: Likewise.
 * riscv-opts.h: Likewise.
 * riscv.md: Likewise.

gcc/doc:
 * extend.texi: Added documentation for the XCOREVBITMANIP
   extension builtins.

gcc/testsuite/gcc.target/riscv:
 * cv-march-xcorevbitmanip-compile-bclr.c: Added new tests.
 * cv-march-xcorevbitmanip-compile-bclrr.c: Likewise.
 * cv-march-xcorevbitmanip-compile-bitrev.c: Likewise.
 * cv-march-xcorevbitmanip-compile-bset.c: Likewise.
 * cv-march-xcorevbitmanip-compile-bsetr.c: Likewise.
 * cv-march-xcorevbitmanip-compile-clb.c: Likewise.
 * cv-march-xcorevbitmanip-compile-cnt.c: Likewise.
 * cv-march-xcorevbitmanip-compile-extract.c: Likewise.
 * cv-march-xcorevbitmanip-compile-extractr.c: Likewise.
 * cv-march-xcorevbitmanip-compile-extractu.c: Likewise.
 * cv-march-xcorevbitmanip-compile-extractur.c: Likewise.
 * cv-march-xcorevbitmanip-compile-ff1.c: Likewise.
 * cv-march-xcorevbitmanip-compile-fl1.c: Likewise.
 * cv-march-xcorevbitmanip-compile-insert.c: Likewise.
 * cv-march-xcorevbitmanip-compile-insertr.c: Likewise.
 * cv-march-xcorevbitmanip-compile-ror.c: Likewise.
 * cv-march-xcorevbitmanip-fail-compile-bclr.c: Likewise.
 * cv-march-xcorevbitmanip-fail-compile-bitrev.c: Likewise.
 * cv-march-xcorevbitmanip-fail-compile-bset.c: Likewise.
 * cv-march-xcorevbitmanip-fail-compile-extract.c: Likewise.
 * cv-march-xcorevbitmanip-fail-compile-extractu.c: Likewise.
 * cv-march-xcorevbitmanip-fail-compile-insert.c: Likewise.

gcc/testsuite/lib:
 * target-supports.exp: Added proc for the XCOREVBITMANIP extension.

Signed-off-by: Mary Bennett <mary.bennett@embecosm.com>