XCOREVMAC builtins added

gcc/common/config/riscv:
  * riscv-common.cc: Added XCOREVMAC

gcc/config/riscv:
  * corev.def: Added XCOREVMAC builtins.
  * corev.md: Likewise.
  * riscv-builtins.cc: Likewise.
  * riscv-ftypes.def: Likewise.
  * riscv-opts.h: Likewise.
  * riscv.md: Likewise.

gcc/doc:
  * extend.texi: Added XCOREVMAC builtin documentation.

gcc/testsuits/gcc.target/riscv:
  * cv-march-xcorevmac-compile-mac.c: Added compile tests for new builtins.
  * cv-march-xcorevmac-compile-machhsn.c: Likewise.
  * cv-march-xcorevmac-compile-machhsrn.c: Likewise.
  * cv-march-xcorevmac-compile-machhun.c: Likewise.
  * cv-march-xcorevmac-compile-machhurn.c: Likewise.
  * cv-march-xcorevmac-compile-macsn.c: Likewise.
  * cv-march-xcorevmac-compile-macsrn.c: Likewise.
  * cv-march-xcorevmac-compile-macun.c: Likewise.
  * cv-march-xcorevmac-compile-macurn.c: Likewise.
  * cv-march-xcorevmac-compile-msu.c: Likewise.
  * cv-march-xcorevmac-compile-mulhhsn.c: Likewise.
  * cv-march-xcorevmac-compile-mulhhsrn.c: Likewise.
  * cv-march-xcorevmac-compile-mulhhun.c: Likewise.
  * cv-march-xcorevmac-compile-mulhhurn.c: Likewise.
  * cv-march-xcorevmac-compile-mulsn.c: Likewise.
  * cv-march-xcorevmac-compile-mulsrn.c: Likewise.
  * cv-march-xcorevmac-compile-mulun.c: Likewise.
  * cv-march-xcorevmac-compile-mulurn.c: Likewise.
  * cv-march-xcorevmac-fail-compile-mac.c: Likewise.
  * cv-march-xcorevmac-fail-compile-machhsn.c: Likewise.
  * cv-march-xcorevmac-fail-compile-machhsrn.c: Likewise.
  * cv-march-xcorevmac-fail-compile-machhun.c: Likewise.
  * cv-march-xcorevmac-fail-compile-machhurn.c: Likewise.
  * cv-march-xcorevmac-fail-compile-macsn.c: Likewise.
  * cv-march-xcorevmac-fail-compile-macsrn.c: Likewise.
  * cv-march-xcorevmac-fail-compile-macun.c: Likewise.
  * cv-march-xcorevmac-fail-compile-macurn.c: Likewise.
  * cv-march-xcorevmac-fail-compile-msu.c: Likewise.
  * cv-march-xcorevmac-fail-compile-mulhhsn.c: Likewise.
  * cv-march-xcorevmac-fail-compile-mulhhsrn.c: Likewise.
  * cv-march-xcorevmac-fail-compile-mulhhun.c: Likewise.
  * cv-march-xcorevmac-fail-compile-mulhhurn.c: Likewise.
  * cv-march-xcorevmac-fail-compile-mulsn.c: Likewise.
  * cv-march-xcorevmac-fail-compile-mulsrn.c: Likewise.
  * cv-march-xcorevmac-fail-compile-mulun.c: Likewise.
  * cv-march-xcorevmac-fail-compile-mulurn.c: Likewise.

gcc/testsuite/lib:
  * target-supports.exp: Added XCOREVMAC proc.

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