gdb: Add riscv to list of architectures with a save_reggroup

The regcache cooked_read test needs to know which architectures have a
save_reggroup, riscv does and needs adding to the list.

gdb/ChangeLog:

	* regcache.c (cooked_read_test): Add riscv to the list of
	architectures that have a save_reggroup.

gdb/ChangeLog

@@ -1,3 +1,8 @@
+2018-03-07  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* regcache.c (cooked_read_test): Add riscv to the list of
+	architectures that have a save_reggroup.
+
 2018-03-07  Andreas Arnez  <arnez@linux.vnet.ibm.com>
 
 	* gnu-v3-abi.c (gnuv3_rtti_type): Add early exit if the given

gdb/regcache.c

@@ -1695,7 +1695,8 @@ cooked_read_test (struct gdbarch *gdbarch)
 	      || bfd_arch == bfd_arch_msp430 || bfd_arch == bfd_arch_mep
 	      || bfd_arch == bfd_arch_mips || bfd_arch == bfd_arch_v850_rh850
 	      || bfd_arch == bfd_arch_tic6x || bfd_arch == bfd_arch_mn10300
-	      || bfd_arch == bfd_arch_rl78 || bfd_arch == bfd_arch_score)
+	      || bfd_arch == bfd_arch_rl78 || bfd_arch == bfd_arch_score
+	      || bfd_arch == bfd_arch_riscv)
 	    {
 	      /* Raw registers.  If raw registers are not in save_reggroup,
 		 their status are unknown.  */